The Harrison Design 1911 Low Mount U Notch Rear Sight offers 1911 pistol owners the opportunity to upgrade the fixed sights on their guns, thanks to the innovative construction of this rear aperture. The Harrison Design 1911 Low Mount U Notch Rear Sight is CNC machined using bar-stock carbon steel and features a durable, heat-treatment, along with a matte-black oxide finish. The U-notch design allows for quick and easy sight acquisition and is completely machine-radiused for concealed-carry use. Rear blade features 50 LPI serrations 8-32 set screw secures sight into dovetail Fits Novak LoMount slide dovetail Works with .325-inch front-sight blades The Mfg: Harrison Design & Consulting