AimShot MTMQR-40PR Quick Release M-Lok Adapter - Picatinny Rail 40mm, Tool free M-Lok quick release for mounting accessories to M-Lok rail sections. 40mm = 1.50" Comes with 4 slot picatinny rail that is low profile. Works great to attach most metal accessories to the M-Lok rails. Some plastic accessories (Vertical Fore Grips typically) need more height. Tool free mounting on M-Lok rails. Larger buttons make it easier to mount and remove quick detach from rails.