Mancraft sent in news last week that the Mancraft Air Stock Support MK1 or M.A.S.S. is now on pre-order. This kit allows you to install an HPA tank and regulator in the stock rather than running a line to an external tank to power an HPA-powered rifle. Also, they have the Mjolnir adjustable sound amplifiers available now.
"M.A.S.S. available on preorder:
