The Bow Master Aluminum CNC Rail Stock Adapter is designed for the Tokyo Marui MP5A5 Next Gen Recoil Shock electric SMG and the Umarex (VFC) MP5A5 Gas SMG. This is an easy to install accessory designed to allow the shooter to use picatinny rail mountable stocks or sling mounts for alternative usage. You can either opt for a more modern stock or do away with the stock altogether, making your MP5 more compact!