Truglo TG13WA3PC TFX Pro Sight M2 Pro Set Fits: Walther P99 and PPQ Hermetically sealed TFX Capsule provides maximum protection of Tritium and Fiber-Optic elements from oils, chemicals, and cleaning solvents Contrasting colored front sight ring for even faster focus Black Retention Rings improve front sight acquisition and reduce glare Quick and accurate U-notch Design