Magpul

-Mounts on mil-spec sized carbine receiver extension tube (not included) from manufacturers such as Colt, LMT, Ruger, S&W, SIG, and others (please see the note below)-Sloping cheek weld combines a slim profile with user comfort-Shielded release latch prevents snagging & accidental operation-Premium chrome-silicon lock spring provides positive locking & long service life-Side mounting slots accept optional cheek risers for NON AR15/M4 applications-Removable 0.30" Rubber Butt-Pad offers an anti-slip surface & increases impact protection-Compatible with Magpul ASAP®, ASAP® QD, & other receiver-mount sling attachments-Sling Mounts -Rear/Bottom - 1.25" sling loops -Toe - Lanyard hole for custom para-cord rigsNote: There are two basic sizes of M4 Carbine receiver extensions (buffer tubes): mil-spec & commercial-spec. If you have a commercial-spec size extension on your rifle, make sure to order #MAG401