Improve low-light aiming on Smith & Wesson M&P Shield pistols with the Trijicon SA39-C-600714 Night Sight Set. Battery-free tritium-phosphor lamps support dependable sight acquisition when ambient light is limited.Shock-resistant construction, a sapphire window, and white alignment rings deliver consistent illumination and clear front-sight definition during use.Fits Shield .40, .45, and 9mm models.Tritium-phosphor lamps operate without batteries.Sapphire window distributes illumination evenly.Silicone cushion absorbs operational shock.Protective aluminum cylinders improve durability.White rings aid rapid sight alignment.Professional installation is recommended.Choose professional installation for proper fit and dependable system performance.