This is a Fusion Custom, Mil Spec style rear Night Sight. Green Trijicon tritium with White outline, great for all light conditions. Standard Colt, 70, 80, 90 series Mil spec style dovetail, 50 Degree x .330 dovetail. Dovetail also has Locking screw & Wrench to retain sight in dovetail. This is one of the best rear sights for quick target acquisition in all lighting conditions. Standard Milo Spec Colt 70, 80, 90 series dovetail base, which is the most common rear mil spec style sight dovetail. Used by many manufactures such as RIA, Colt, SAM, ...etc.1911 Colt Mil spec style pistols & Clones. .. CNC Machined from steel bar-stock with black oxide finish…. MADE in the USA….. Trijicon Tritium.