Leapers Low Profile Flip-Up Rear Sight is constructed of aluminum with a black finish and a low profile 3mm locking bolt and mounting deck. Features: UTG new gen super slim flip-up rear sight for the AR platform and other long gun applications equipped with Picatinny rail Precision machined from aircraft grade aluminum with black anodize Spring loaded posi-lock design with side plunger release for positive flipping/folding; compress plunger to unlock and fold down when not in use Robust posi-lock plunger coupled with spring activated ball bearing guarantees zero retention Complete with dual aiming apertures ideal for moving target engagements and limited visibility or normal firing situations Low profile 3mm locking bolt and mounting deck securely attaches to any Picatinny rail Designed to match MNT-755 new gen super slim flip-up front sight on same level plane applications