These adjustable sights are identical to the old original Bo-Mar adjustable sights, which are no longer available. Rear Sight is made to withstand the shock of service ammunition, with rugged, dependable features designed to please the competitive pistol shooter. Works perfect with our #1624 front sight. These are the highest quality and tightest tolerances available. Fully adjustable for both drift and elevation. Engraved “ED BROWN” on the side. Notch width is approximately 0.115. Dovetail is 60 degrees x 0.359. Available in blue only. We recommend installation by a competent gunsmith.