Fits 1911/2011 platforms. (Professional Gunsmithing Required) Trijicon RMR mount with integrated night sights allow lower 1/3 co-witness of the front post. Requires slide machining by a professional gunsmith. Fits all Trijicon RMRs. The 1911 RMR mount with integrated back up iron sight is a fixed rear sight solution. To achieve windage adjustments for point of aim (POA) point of impact (POI) the gunsmith must drift the front sight left or right. Move the front sight in the opposite direction you wish the point of impact to move. Gunsmith is responsible for establishing correct height relationship between the front and rear sight. Correct height can be achieved by referencing the bottom of the front dovetail and milling the slide to the desired depth (see below). If adequate height relationship cannot be achieved by changing milling depth, alternate height front sights are available.Features:Instantly visible sight picture in no-light and low-light situations - Tritium phosphor-filled glass lamp provides battery-free glow, allowing for a visible sight picture in all lighting situationsIncreased daylight dot visibility - white painted rings around tritium lamps enhance user's ability to see sight picture in bright-light shooting situationsEnhanced protection from heavy recoil and harsh cleaning solvents - Tritium gas lamps are contained within protective aluminum cylinders and have additional silicone rubber cushioningEvenly distributed light from Tritium lamps - each Trijicon Tritium lamp is capped with a sapphire jewel that helps evenly distribute the light from the lamp and also acts as an additional layer of protection from puncture and cleaning solvents