146533 Includes: TC Ambidextrous safety selector, TC AR takedown pins, TC Magazine release button, Mounting hardware included. (Mil-spec bolt catch, springs, and pins are required to complete build) The Timber Creek AR-15 Lower Parts Kit provides quality parts needed to start any MSR build. These high-quality parts are CNC machined from aircraft-grade billet aluminum. Photos show the exact item where applicable. Have questions? Reach out to Bay State Surplus and we'll get you squared away.