Improved replacement rear sight MOUNTING BRACKET and HIGH STRENGTH SCREW for the MATECH Back-Up Iron Sight (AR15/M16). Improvements include: (1) Thicker and Stronger Mounting Bracket - CNC'ed out of solid bar stock steel, not cast or metal injection molded. (2) Stronger Screw - approx. double the yield strength of the original screw (3) Countersink Hole - allows the screw head to be semi-recessed (4) Re-Aligned Screw Hole - minimizes canting of the screw (5) Smaller Allen Head Socket - minimize over torquing

***FREE FIRST CLASS MAIL SHIPPING!***