This is a XS Sights known as the RAM, model SW-R033S-6N.
XS RAM (RadioActive Material) Tritium Night Sights feature a traditional 3-dot tritium" notch and post sight picture. The rear is blacked out to increase contrast against the front sight. The front sight is available in orange or green and is equipped with XS's Ember Glow Dot Technology. Ember absorbs ambient light and glows in low light. The front tritium lamp charges the Ember dot making the front sight glow brighter than the rear" keeping focus down range. RAM sights are the brightest options for fast and accurate shooting in bright and low light.
Features:
Tritium Powered Front & Rear Sight -Glows in low light to aid in sight alignment
High-Contrast Color Front Sight - Available in bright orange or green
Ember Glow Dot - Photoluminescent dot absorb ambient light and glows in low light
Rear Sight Overhang - Reduces rear sight glare in bright light for greater sight definition
Anti-Reflective Rear Tritium Lens - Reduces glare in bright light and increases contrast against the front sight
Rear Sight Ledge - Aids in one-handed slide manipulations
CNC Steel - Extremely durable for duty use
10 Year Warranty - No Questions Asked Night Sight Warranty
Easy Installation - Easily install by hand or sight pusher tool
Fits standard holster options