There are 4 things that open doors. Introducing the K.T.M.S. 12. A barrel mounted Remington 870 AR15 attachment. Originally made famous as the Masterkey, this clone is constructed using modern guns and manufacturing processes. This was a collaboration between Tyr 1 Outfitters as the exclusive distributor and Allegheny Gun Works. The K.T.M.S. 12 will attach to M4 cut barrels both government and SOCOM profile. The barrel hanger mount is of our own design and attached to the barrel via a two piece mount. The The K.T.M.S. 12 will also attach to Daniel Defense Ris II rails via theor integral M203 mounting system. The LMT QD mount is directly compatible and can attach to the unit should the end user choose to swap it out.