The KP-9 is a monolithic polymer 9mm Glock Mag Compatible AR15 style receiver made from injection molded 30% glass filled nylon incorporating the buttstock, buffer tube, pistol grip, and trigger into the receiver design as integral components. This manufacturing process offers several advantages, such as lighter weight compared to similarly configured receivers, lower cost to similarly configured receivers Features Include: Compatibility with most common 9mm AR15 uppers and lower parts kits Compatible with Glock 17 and 19 Magazines Flared magwell to make reloads under stress easier to perform. A1 Length 13" Length of Pull (LOP) Buttstock to f Mfg: Ke Arms