Tactical Smart Polymer Front and Rear Flip Up Sight Combo Set by Sniper(R).High Quality flip-up front and rear sight towers complete with A2 square post assembly with locking retention and precision elevation adjustments for greater accuracy.Mounting Decks designed to be used with hand guard rails or front gas blocks (front sight tower) and both will fit all 7/8". Allen Wrench With Locking Retention For Maintaining Zero Under Heavy Conditions. Tactical Combo Of Front And Rear Polymer Sights. Quick Detachable Front Sight with Adjustable A2 Square Post Assembly to Fit All Picatinny/Weaver Style Rails. Equipped with Locking Retention Allen Wrench and Clever and Robust Flip-up Posi-lock Precision Elevation Adjustments to Enhance Shooting Accuracy. Profile Designed for Installation on Gas Block. Integral Picatinny Mounting Deck to Fit All Flat Tops. Dual Aiming Apertures for All Shooting Requirements. Precision Windage Adjustments. User Friendly Locking With Allen Wrench for Easy Installation. Backup AR15 AR-15 M16 M4 M-4 Flattop A1 A2 Post Back Up.* Complete with A2 Square Post Assembly, Locking Retention* Precision Windage and Elevation Adjustments* Clever and Robust Flip-up Posi-lock Design to Guarantee Zero* Dual Aiming Apertures* Lightweight and Durable* 1" Height*For best results tighten fastener to a minimum of 20 in/lbs