Mounts on mil-spec sized carbine receiver extension tube (not included) from manufacturers such as Colt, Armalite, S&W and LMT.Sloping cheek weld combines a slim profile with user comfort.Shielded release latch prevents snagging and accidental operation.Premium chrome-silicon lock spring provides positive locking and long service life.Side mounting slots accept optional cheek risers for NON-AR15/M16 applications.Removable 0.30" Rubber Butt-Pad offers an anti-slip surface and increases impact protection.Compatible with Magpul ASAP and other receiver-mount sling attachments.Sling Mounts.Rear - Push-button QD swivel sling mount accommodates up to 1.5" swivels.Rear/Bottom - 1.25" sling loops.Toe - Lanyard hole for custom para-cord rigs.