Precision wired then CNC machined from heat treated 4140 bar stock. Dovetail is 65 degrees x 0.495. Sight height is 0.325″. The U-notch allows for quick instinctive alignment with a dot front sight, such as our fiber optic, gold bead, or tritium front sights. The rear is serrated at 40lpi to reduce glare. The front surface of the rear sight is steeply hooked to assist in emergency one-handed slide operation. The 0.140″ notch makes for a nice compromise between accuracy and a wider notch for quicker acquisition of a dot front sight.