Aluminum receiver extension replaces the standard, fixed buttstock on your AK-47 to let you install an M4 collapsible stock on your rifle. Provides five locking positions; corresponding white index numbers are visible through the release pin access hole found on many buttstocks. Near-receiver sockets on each side of the extension accept quick-detach, push-button swivels for single-point sling attachment. An internal storage compartment is accessible by removing screw-on cap from the rear of the extension. Includes mounting hardware. SPECS: Aluminum, hardcoat anodized, matte black finish. 8” (cm) overall length. Fits most AK-47/AKM/AKS rifles with stamped receivers, except the Yugo RPK and Iraqi Tabuk. Accepts Colt and other mil-spec collapsible buttstocks that fit a 1.14” dia. buffer tube. Kit includes stock extension, end cap, mounting bolts, nut, (3) dust plates, and installation instructions.