The Meprolight Hyper-Bright Plus Green Tritium Front & Rear Blue Ring Sight Set is a premium, battery-free tritium sight upgrade purpose-built for non-optics ready S&W M&P full size, compact, sub-compact, SD, and SDVE models, featuring premium Swiss-made green tritium vials in both the front and rear sights and a bold blue contrast ring on the front for fast, instinctive daytime target acquisition. The U-notch rear sight naturally guides your eye directly to the front sight for a clean, consistent sight picture in any lighting condition, while the ultralight snag-free steel construction is drop-proof, shockproof, and installs directly on the factory slide with zero modifications required. Requiring no batteries and backed by a 12-year tritium illumination guarantee, these sights are always on and always ready — 24 hours a day, 7 days a week.