Wolverine Airsoft HPA Systems WRAITH Dual Airsource Kit.

This kit allows you to switch between running CO2 through your Wraith stock and an external air source (HPA tank). See this video for installation instructions: 

Includes : Filtered Grip Connect fitting, Check valve, Union Tee, 6mm tubing

*Note : The Dual Air Source Kit is only compatible with AEG conversions, not the MTW