The Meprolight R4E Optimized Duty Sights are a unique tritium equipped night sight, with additional vertical and horizontal sight markings for optimum sight alignment, and faster sight acquisition. The R4E features three vertical features and two horizontal lines to a reticle type sight picture that improves target acquisition time and increases precision. The Tritium enhanced lines on the rear sight and front dot help improve target acquisition in low light conditions. Designed to fit all For Glock full size pistol models these unique night sights are ideal for military, law enforcement or carry use.