RA Challenge DIY Pack for GHK M4
OptimusPrime
22 Dec 2014
Whilst doing production for the RA Forged Receiver for the GHK M4 GBB Series, RA-Tech decided to make it even more challenging. They added a version called RA Challenge DIY Pack for the GHK M4 so it's a kit that comes with upgrade parts to do your own upgrade... "Upgrading requires necessary assembly skill & technique, consult expertise if needed."