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. Note: 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.