An airsoft shotgun,, the Jag Arms Scatttergun gets modded for it to use HPA as power source. The Real Deal Airsoft shows how it is done... "How to HPA Tap an #airsoft​ shotgun. This mod only works with the Green Gas Scattergun by jag arms.

You will see step by step what is required to convert your gas shotgun to hpa shotgun.

Benefits of HPA are:

We call this shotgun from JAG Arms, the "Cutie Shorty" as it looks the handiest compact shotgun in the airsoft market. Here is Airsoft GI to tell more about this and here is the description from JAG Arms... "The wait for reliable and affordable gas shotgun is over; featuring JAG Arms Scattergun Gas Shotgun Series.