Trijicon Bright & Tough Night Sights feature a shock-resistant design and lamps capped with sapphire jewels to help evenly distribute the light while still providing resistance to solvents to the lamp. The lamps are also cushioned with silicone rubber and are contained within aluminum cylinders for additional protection.
The SA05 is for guns made before Novak sights (before late 1989). It fits models 3904, 3906, 6904, and 6906.