CNC machined sight post has integral crosshairs to provide quick, consistent sight alignment for improved accuracy at any range. Large diameter aperture offers a wide field of view that does not obscure target; gives a sight picture that's like looking through a scope. Compatible with factory rear sights and variable-diopter target sights. Non-hooded AR-15 sight is .082" thick. Hooded sight has .250" hood that shields crosshair from reflected light, offers greater crosshair protection for extreme duty use. STD, thin wire crosshair. AR-15 available as Hooded or non-hooded, fits M-16 and AR-10 rifles with standard sight housings. L1A1, FN-FAL and 3/8" sights are Hooded. 3 Mfg: Kns Precision SPECS: Brass, black, matte finish. Beryllium crosshairs, heat treated. STD - .010" (.25mm) wire, .240" (6.1mm) diameter aperture. HK 91 fits 91, 93, 94 MP-5, SP-89. 3/8" Dovetail height measured from top of base to center of sight.