The Magpul CTR (Compact/Type Restricted) – Commercial-Spec Model is a drop-in replacement buttstock for AR15/M16 carbines using commercial-spec sized receiver extension tubes. Designed for light, fast action the streamlined A-frame profile avoids snagging and shields the release latch to prevent accidental activation. The CTR also features a supplemental friction lock system that minimizes excessive stock movement for enhanced weapon stability* and an ambidextrous QD sling mount that will accept any push-button sling swivel. The Commercial-Spec Model includes an extended 0.55" rubber butt-pad to provide positive shoulder purchase and accommodates the longer, slanted back common to most commercial-spec tubes.