BKL Single 30mm Single Strap Ring, 3/8" or 11mm Dovetail, .60" Long, Black BKL Single 30mm Single Strap ring Fits 3/8" or 11mm dovetail 0.60" clamp length 0.60" ring length 0.60" overall length 0.979" from bottom of mount to bottom of scope tube 1 hex screw secures the base 2 hex screws on the ring cap Black 2.20 oz. Includes 1 (one) ring and a hex wrench