Polished and Blued Steel. Sweat-on models have one attaching screw. Screw-on models have 2 attaching screws; one under sight and one on ramp. Mfg: Williams Gun Sight SPECS: Fractional height listed in table is the overall ramp height measured from top of barrel to top of ramp. Decimal height listed is measured from top of barrel to bottom of dovetail. Width of ramp is .250" (6.3mm). Supplied without hood. 3/16 screw on ramp has 1.625" center to cen