Knight's Armament 45 degree offset micro sight set include one front and one rear micro flip up sight. The front sight mounts to M4/M5 RAS, Free-Float RAS or any railed handguard that is at the height of a flat top upper receiver. Flip-up sight stays down out of the way when using optics, yet is easily flipped up. Mounts at a 45 degree angle to allow operator to cant the rifle slightly to access the iron sights while keeping any optics mounted to the rifle, works best for right hand shooters. Front sight has adjustable elevation without tools using the thumb wheel. Rear sight is similar to Knight's Armament's 200-600m micro sight. Sight has a large aperture with removable plastic insert with small aperture. BUIS mounts to any AR-15/SR25 flat top receiver. Sight is elevation adjustable by turning the body of the flip up portion. Windage is adjustable by turning the micro knob on the side of the sight.