Leapers Spring-Loaded Low Profile Flip-Up Front Sight for the AR15 is constructed of aluminum with a anodize black finish with a low profile. Spring-loaded posi-lock push button activation automatically deploys sight tower and prevents sight tower from collapsing when deployed. Uses Standard A2 Front Sight Post, Interchangeable with other aftermarket posts with equivalent dimensions. Utilizes a single locking Torx screw with low profile mounting Base. Uses 3mm locking bolt and mounting deck, Torx locking plate recommended torque value: 35 in-lbs. Requires sight tool. Front sight post width:0.07", post height: 0.26".