Aimsports AR Low Profile front sight is for use with standard height AR-15 rear sights. Features- ball bearing pivot detent, automatically locks into position when raised, flip-up posi-lock design to guarantee zero, quick detachable with adjustable A2 square post, uses standard A2 sight post 0.02″ and same plane handguard/upper receiver height. 0.65 MOA on 16″ rifles and 0.49 MOA on A4 20″ rifles.