According to Wolverine Airsoft, the WRAITH X makes your airline obselete. Watch the video to find out... "The all-new WRAITH X with built-in STORM Category 5 regulator allows you to run your HPA engine with 12 gram or 33 gram CO2 cartridges concealed in the buffer tube or to utilize a standard 13/3000 HPA tank to get approximately 1,000 shots per tank!"