PolarStar Airsoft demonstrates how to install their CGS with the Gas Stock Adapter on the JAG Scattergun airsoft shotgun... "This Gas Stock Adapter allows you to configure your JAG Arms Scattergun with our CGS air system so the gun can be converted to run off of 12g or 33g CO2 instead of green gas. The adapter has metric threads on one side to interface with the original JAG Scattergun buffer tube socket and a TM spec stock tail on the other to interface with the Type 2 CGS."