There's always a collective yawn whenever an airsoft gun is released in a line that's already been  peppered with versions from too many manufacturers. We can always identify the following:  M4s/M16s, AK47s, SIG5XX, and of course the MP5 line. But what we are about to tell you is  something different from your usual MP5-inspired AEG, and this one's released by ICS last September 2010, with over a year of development, testing and refinements before it got released.

The MX5-Pro from ICS is comprised of three variants for now: the ICS-18 A5 Retractable Stock; the ICS19 MS1 Folding Stock; and the ICS-110 Fixed Stock for those who prefer the classic stock. The MX5-PRO Series is different from the old MX5 Series, though they share the same lineage as having the split gearbox technology that only ICS has. This split gearbox technology is the most  distinguishable thing about the Taiwanese company.

We were privileged to be provided a review unit by ICS, coursed through Firesupport. We were  intending to review the MS1 version as it is the most radical among the three variants given its  different folding stock and pistol grip. However, it seemed that the stock of the MS1 was almost depleted when it got released and the ICS-18 (A5) was available. We didn't mind since apart from  the differences in external features, they all feature the improvements in ICS' split gearbox technology.

The A5 was with us for a month now, and we went through the paces of testing it before we sat down and wrote what we think of this AEG. The first thing that we can tell is that we can write less  about this than the MS1 as there are features of the AEG we would love to abuse and determine if  those features are useful or utterly useless. The A5 is more a simple design, not as gorgeous as the MS1, but nevertheless performs  like the MS1 as well with its new generation ICS split gearbox.


The package that the ICS MX5-Pro A5 is typically what you expect from ICS--- a well thought-out box and does not crumple easily as compared to some manufacturers' boxes. We were expecting to be a little bit more on the heavy side just like the Systema TW5, but, we were surprised that is actually easy enough at around 2.8kg (without the magazine). What the package includes are two 230 round magazines, a bottle of ICS BBs, and the manual.

Our first impression is it's a little bit on the glossy side, but we started to appreciate the build material of this AEG. What is a plastic is industrial grade plastic material, and the upper receiver is made of stamped steel. What you will immediately notice at the front area of the AEG is its rather wide handguard. ICS has plugged the muzzle with an orange muzzle cap, which is good for transporting the AEG with its muzzle cap on. It also protects the inner barrel from dust getting inside whilst in storage. Removing the muzzle cap show the inner barrel which has an inner diameter of 6.08mm.

The handguard has rail mounts on both sides to mount accessories and it is comfortable to hold despite it's non-sleek look. Whether you have tiny or large hands, you will assure yourself of a solid AEG. ICS constructed the handguard, despite a hollow cavity inside as the battery compartment, with a tenacious claw-like grip when installed, allowing no movement nor flex whilst you're holding it tight.

The charging handle, just like the Systema TW5, is a sheer delight to handle. Pulling the charging handle back and locking it into place, it opens the port on the other side to reveal the hop-up area. The delight part comes when you slap the charging handle down for it to slam back into position, giving a great "cha-clack"" that you hear in movies about SWAT teams going lock and load. We couldn't resist such function, even if it's minimal, it's nice practising with the charging handle. In fact, we tried to do the same action over and over again, perhaps around 100
"pulls and slaps" to see if the spring loosens up and the charging handle gets flimsy. To our  surprise, the charging handle gets back into place just like brand new. It is really a sturdy feature of the ICS AEG.

The magwell comes with a KAL.9.mmx19, though of course our rounds are 6mm bbs, and this just a cosmetic feature. The A5 does not sport any other markings apart from this and the fire select modes. Inserting and pulling out a magazine is something to be desired, it's not smooth enough. We tried our skills at magazine change proficiency, and I have enough experience with MP5s to develop speed in magazine change. The A5 frustrates me in such area. whilst I have nothing to say about its great construction, ICS should have checked further to ensure that magazine change won't be such a chore, since speed is of the essence always.

Putting the experience aside. I love how the A5 looks like at the magwell with magazine inserted. Perhaps its due to how took the photo that produced this profile look. It looks really sleek and nice looking.

ICS have a great reputation with their TM-compatible magazines as they're some of the more preferred magazines to use due to their durability and minimum feeding issues. The engineers of ICS not only took great care of the internals of this magazine, but also the external, which we can say for sure that the ICS MX5-PRO magazine is the best magazine for its class. However, whilst you what you can see in the photos is a high-capacity magazine, you should not assume its loading capacity in the same league as the M4 or AK AEG magazines. Being such a slim magazine, the MX5-PRO magazine can only carry a maximum of 230 rounds. I am not complaining though, since ICS have already tossed in an extra magazine making it around 460 rounds available for you to use when you dive into a CQB game somewhere.

In a single full magazine firing test, we love its ability to serve the bbs required by the gearbox to push out of the AEG. A good wind of the magazine allowed us to have a continuous stream of bbs for several seconds.

The MX5-PRO series boast of their “burst technology”, meaning that this is the other MP5-like AEG that has the three-round burst mode. It competes against Systema in this regard, and we can say that it surpasses the Systema TW5 series in terms of reliability and build quality. Both the MX5-PRO and the TW5 have ambidextrous fire selector switches but our experience with the Systema TW5 was ambivalent at best. The MX5-PRO ambidextrous fire selector switch is solid and both switches would move at the same together, the TW5, well, the right selector switch sometimes falls off whenever we switch firing modes.

Switching between modes, the assurance that it is in the desired mode is good. When we tried firing at semi, three, and full auto, the response of the gearbox and motor was excellent and crisp. whilst the TW5 gives you a more subdued sound, the MX5-PRO is loud. But the reliability of the “burst mode” is very much welcome for those who are economical in bb use, which includes me. I rarely use single/semi modes in games, unless it is required, and this “burst mode” is something I prefer when avoiding full auto modes, as it gives me some comfort that if a single round misses the target (or if the target doesn't call the hit with the first round), the second and third one would make sure that you get that hit that you want.

ICS have the patented H2E electronic control in the MX5-PRO series which is said to “regulate voltage, increase the battery life, save power consumption, and increase the life of motor. It also has high durability and humid resistant.” whilst we did not have the tools to check their claims, our experience in the skirmish field seem to support it. Our 9.6v mini battery lasts longer than the usual.

Another innovation that ICS have included in the fire selector switch is the “spring tension release function”. The usual advice to all airsoft players is that after every game and on our way back to the safe zone, we have to remove the magazine and fire the AEG again to ensure that there is no round left in the gun, and also to release spring tension so that the AEG spring lasts longer. With the ICS “spring tension release function”, whenever you push the fire selector switch back to safe mode, you will hear a whirring sound which is the gearbox having the spring go back into a non-tense position. This removes the concern of spring tension after firing the AEG, no need to fire again to make sure the spring is in normal position.

The retractable stock is a cinch to use. Made of stamped steel, it is very rigid and we tested it by having a two foot drop to the ground and it is indeed very durable. The buttpad is nicely made and ICS say that they made it with injection moulding, the same process as those used in real steel guns. The stock is securely attached to the rear adaptor which also serves as the rear cover for the gun. A lever to adjust retract or adjust the stock is also located at the rear adaptor and you by turning the lever to the left, you release the lock and make the adjustments. The action is smooth, both for the lever and the skeletal stock.

The rear sight of the MX5-PRO A5 is still the standard MP5 rear sight, and it goes the same for the front sight. There are no markings for the sight, but it is easy to understand when you adjust the sight as you will know which part is for precision shooting and one for snap shots by turning the knob which also adjusts the height. As for moving the sight from left to right and vice versa is by turning the screw located on the right side of the rear sight. However, before you can adjust the orientation of the rear sight, you need to loosen the screw located at the back of the rear sight. You will need a screw driver to do such action.

If you get the MX5-PRO MS1 variant, you will notice fully redesigned rear and front sights. For the rear sight you are reminded of an M4 rear sight. The front sight of the MS1 is also interchangeable, and you can select different sight posts that will suit your taste.

Changing batteries is easy, but a little bit of a chore as the handguard has a clawl-ike grip. You will need to push out the securing pin located near the front out before you can remove the handguard. As the handguard is industrial strength plastic, you can force to loosen its grip on the gun frame to remove it without worrying that you'll crack it. Once you remove the handguard, you will then notice the battery connector and a cavernous space. This is generous and you can place a 3-3-2 9.6v battery inside. If you use the standard 1600mah 9.6v like I do, there is still enough space to put something extra, perhaps some small tools you will need.


The Manual provided is very straightforward, however, it didn't go all the way in terms of giving you instructions to dismantle everything. We are all familiar with the upper part of the ICS split gearbox technology, but the lower part of the split gearbox is a new animal in itself. whilst ICS says that opening the gun doesn't need tools --- partly, you can open it up with the pins without any tools, but going inside still require tools when you take out the lower part of the gearbox.

First things first before you try to split the receiver to take out the split gearbox, you will need to remove the stock and the stock adaptor.

From thereon, you can raise the upper receiver and pull out the upper part of the gearbox if you want to change the spring. Once you remove the upper part of the gearbox, you can also pull out the charging handle spring.

We will not go pointing out the finer details of the inner barrel, hop-up, spring, and also the rest of the upper gearbox.  We will focus more on the lower part of the ICS split gearbox as it is where the most interesting parts of the internals are found.

To finally split the whole gun into its external components, you pull out the pin at magwell area and pull out the lower receiver from the upper receiver. Voila! Now everything's put aside to give you a clear way to taking out the lower part of the split gearbox.

As you can see in the photo below, there are things to be excited about in the improved split gearbox technology of ICS. You can see the thick gears and electronics that would rival the electronics of Systema's ECU. To start taking out the lower gearbox out of the lower receiver you'll need to remove the motor plate at the base of pistol grip; remove the screw on the left fire selector switch; pull out the right fire selector switch; and remove the spring and switch mount before pulling out the lower gearbox.

The black box the we removed at the front area of the lower gearbox is the “Advanced Electric Current Break System (AECBS)” which should not be mistaken for the “Active Breaking System (ABS)” which is sort of a spring tension release system that is done electronically by MOSFETs. The AECBS purpose is more on safety as it immediately breaks the current in case the battery is still connected and the firing switch is on when the upper receiver is pulled up. It also lessens the wires snaking inside the gun. No sense of getting some shock when you need to make a quick spring change whilst in the skirmish field, the AECBS is there for your safety needs.

The ICS Turbo-3000 short pin motor is a powerful one, and we're always annoyed when it pulls the screws and pins to it when we were doing the disassembly even whilst inside the pistol grip. Though annoyed, it's just a minor thing, we are happy to note it's a reliable electronic motor.

I like the gearset of the ICS split gearbox as these are made of steel. They are greased adequately for our climate and lubrication is spread out evenly --- no lump of grease to be found. The bushings are oiled steel bushings rather than plastic ensuring that your gears will last longer and lesser friction inside.

The H2E technology is quite interesting. Though we didn't dismantle it as we did not soldering tools with us at the time of the takedown. In our opinion, the latest ICS split gearbox technology has the most number of electrical components among AEG gearboxes.  ICS claims that it is humid resistant so some less worries for you when playing in mild wet weather environment. But since it utilises electronics, we would rather recommend not using this in heavy rain or some simulated water crossing games to avoid shorting the internals.

As per responsiveness of the gearbox with all these electronics, what we can say is that it is on par with responsiveness of Systema AEGs, and much better than other AEGs that use some form of MOSFET. What we are wondering here if there H2E chip is programmable and allows you to do some diagnostics to it to determine if there are some problems with the gearbox. If someone is able to do some reprogramming, it would be great to hear from you.

With the H2E technology, ICS left diagnostics behind, MOSFETs such as the  Extreme Fire series do have diagnostics. It would be great to hear from ICS if they would provide a way for players to tinker with the H2E such as increasing or decreasing power, setting firing modes electronically, and doing some reprogramming on the spot by just using the trigger.

Overall, we are impressed with the gearbox of the MX5-Pro and we sure that ICS would allow some tinkerers to play with the H2E technology and give suggestions on how ICS can eke out more efficiency and functions in this.


We were a little bit apprehensive if this would be allowed in the skirmish field given that many uber-gearboxes nowadays are always too hot out of the box. During chrono it went 333, 331, 330, 331, 331 which is within the allowable limits for us to get to play with this.

In CQB situations, you tend to bump in many areas of the site since things are tighter.  We found that MX5-PRO quite impregnable. The industrial grade plastic whilst, well, plastic, have nary a scratch when some AEGs would already have some wear and tear. We had a metal door almost slam shut and the MX5-PRO stock was used to prevent it from closing and it did the job with flying colours.

After over a month of having this AEG --- dismantling it, abusing it, and playing with it, we are surprised that it still looks brand new. If we want to sell this, it might still get bought at its original retail price. We are lucky that our review unit really has QC written all over and we haven't heard from anyone online complaining about its build quality.

Accuracy-wise, it is quite good especially for CQB situations. At 15 metres, it did provide good groupings, though we would we suggest that you use a tight bore inner barrel if you want it to be laser-accurate for indoor games. 


Are we happy with the ICS MX5-PRO A5? Damn right we are! All the claims of ICS with regards to build quality, innovation, and performance do check out. We could have been happier if we got the MS1 with is like a futuristic MP5 design.

In terms of bells and whistles, the MX5-PRO really deliver a lot of features for a price that is way more than justified than procuring a Systema TW5. Just like the TW5, the MX5-PRO puts more wood into the fire on the  debate of relying too much on the electrical rather than mechanical for AEGs. Surely, the MX5-PRO provides many features that puts it in a rarefied air as one of the finest airsoft SMGs in the market today, leaving behind the competitors, with the exception of Tokyo Marui which also have a lot of tricks up their sleeves. But if electronic failure would  turn your AEG into a big paperweight, then that will be a big point deduction for AEGs like the MX5-PRO.  That's the mixed feelings we're having about the MX5-PRO, but that does not mean that we would not recommend it to other players. We would greatly encourage our readers to consider the MX5-PRO if they are on the market for an MP5 airsoft replica.

With all the bells and whistles and great performance, the retail price of MX5-PRO is even an attractive thing.  It sure does give you a great bang for the buck.

Now the big question is, what else can ICS push into their split gearbox technology? Would they be able to replicate recoil and blowback? Some players would say that it is impossible to implement these with the split gearbox technology and the only way that ICS can improve on is via electronics. Who knows? ICS may just give us another surprise.

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