Truglo TFX Sights are always ready - made from ultra-tough chemical-resistant materials and providing a bright sight picture both day and night helping you stay prepared for any scenario. TFX PRO takes it to the next level offering a contrasting colored front focus ring and U-notch rear sight design for faster sight acquisition and improved accuracy. Additionally the rear sight features an aggressively angled front edge for emergency one-handed operation. Truglo TFX PRO sights are designed for shooters who require the absolute best reliability visibility and accuracy. Contrasting colored front sight for even faster focus Quick and accurate U-notch Design Angled rear sight for emergency one-hand operation All features of Truglo's popular TFX Handgun sights Patented Novak LoMount cut .260 Front / .450 Rear (1911 5" Government .45ACP)* RugerA(R) SR1911 Models (regardless of barrel length). Novak LoMount cut replacement sights are designed for 1911-style handguns with existing fixed Novak LoMount dovetail cut slides however some fitting may be required. Installation by a competent gunsmith is recommended.