Evus designed a speedloader adapter for use with the SCAR-H Gas Blowback Rifle from WE Airsoft... "A speedloader adapter for WE Tech Scar-H. Strength of loading varies on the mags spring (if the spring is worn/settled) and your loader.

Guide on using the item:

1. Place mag in the speed loader adaptor
2. Grip the mag and using your index finger press the top part of the adaptor down (this is necessary on mags with bolt catch to lower the follower). You should see a clear entry to the mag lip from the hole of the adaptor.
3. Insert the speed loader into the hole that is on the adaptor.
4. Put pressure between the speed loader and adaptor, because you will fight the spring tension and to prevent the bbs from exploding when you start to pump the speed loader. (strength required may vary on spring tension, mag brand: some brand uses harder spring, well-worn of the spring, speed loader to be used, the flexibility of the maglip: varies brand-to-brand, etc.)
5. Start pumping the speed loader.

You may also check my youtube video for reference."