The Magpul ACS-L (Adaptable Carbine Stock – Light) is a drop-in replacement buttstock for AR15/M4 carbines using mil-spec sized receiver extension tubes. A streamlined version of the ACS, the ACS-L utilizes the same center storage compartment and cheek weld but removes the battery tubes for a slimmer, lighter weight package. Made in U.S.A. FEATURES: Mounts on mil-spec sized carbine receiver extension tube (not included) from manufacturers such as Colt, Armalite, S&W, LMT, and others (please see the note below) Sloping cheek weld provides a wide contact surface for user comfort