Sergeant Mango does a review of the SRU 3D Printed PDW Carbine Review that allows the user to convert a Glock Gas Blowback Pistol into a carbine. This is designed for the WE Airsoft and Tokyo Marui Glocks 17, 18C and 34 GBB Pistols. The stock can be locked into a folded position and has a rail adapter for mounting weapons accessories.