This is a Trijicon Sight known as the HD, model SA139-C-600721.
S&W M&P Shield(TM) HD Night Sight Set - Yellow: The HD Night Sights were specifically created to address the needs of tactical shooters. The three dot green tritium night sight set's front sight features a taller blade and an aiming point ringed in photoluminescent paint while the rear sight is outlined in black and features a wider U-shaped notch. This unique configuration increases visibility and quickens front sight acquisition-even in transitional lighting. Additionally" the front surface of the rear sight is steeply hooked to assist in emergency one-handed slide operation. Green tritium lamps are warranted for 12 years from date of manufacture.
Features:
Professional installation recommended
Fits both the Smith & Wesson SHIELDâ„¢ .40 .45 and 9mm models
Tritium-Phosphor lamp
Sapphire window
Silicone rubber cushion
Protective aluminum cylinders
Protective clear coat and high visibility colored front sight post
U notch rear sight
Subdued rear sight
