A complete AR-15 featureless-build combo: a fixed (non-collapsing) buttstock bundled with a mil-spec carbine buffer tube kit. This pairing is aimed at builders in restricted-configuration states where a collapsible or telescoping stock triggers "assault weapon" feature rules. The kit ships with everything needed to attach the stock and receiver extension to a lower - no other buffer parts to source. Specs and features: Fixed, non-collapsing AR-15 featureless-configuration buttstock Mil-spec diameter carbine buffer tube (receiver extension) Carbine action spring and standard carbine buffer Steel castle nut and receiver end plate Drop-in fit on any mil-spec AR-15 lower Compatibility: fits AR-15 lowers with a mil-spec 1.148" OD carbine buffer tube. Because this is a fixed stock, the buttstock does not slide on the tube - length of pull is set by the stock body itself, so measure the finished LOP before ordering if you have a preference. Firearm configuration laws vary by state (CA, CT, DC, HI, IL, MA, MD, NJ, NY, RI, VA, WA, and select municipalities); verify your own state and local regulations before purchase or build.