Pew Club Entertainment got this tutorial video to show the how to use the AirTac Hi-Capa To MP5 Mag HPA Adapter... "How’s it going airsofters Do you own an airsoft hicapa? If so this is the video for you!

I can't recommend enough for the Airtac HPA adapter to you!

I was first with so much hatred  with the HPA system for the airsoft at the first glance I thought it would be so clumsy to run an air tank and line most importantly it took out the realism of the replica, however once I tried I realized i was so wrong about HPA.

The benefits of the HPA system on airsoft makes up everything and changed the way I play airsoft. I love my gas blowback but the main fraud is the magazine cooldown effect quite significant  but with the AirTac HPA adapter I could enjoy endlessly fun without cooldown effects.

Cost efficient all you need to do is pump air into the tank."