Meprolight Bullseye Fiber Tritium Sig Sauer P365 Black/White Rear Sight - Green - Based on an optical illumination patent, the MEPRO FT Bullseye is an extremely small, low profile, optical pistol sight. Similar to reflex sights, using the MEPRO FT Bullseye provides the shooter with an aim point in the form of an illuminated dot and circle Bullseye. Shooters can enjoy intuitive and fast target acquisition. The Fiber-optic Tritium combination enables instant and accurate shooting in all lighting conditions with no batteries needed. The Fiber-optic used in bright light or day shooting and the premium-grade Tritium provides instant illumination at night or in low-light conditions. Smallest Optical Sight In The World Based On Patented Optical Illumination Superior Visibility In All Lighting Conditions. No Front Sight Needed Fast And Intuitive Target Acquisition Fits Most Existing Holsters Simple, Easy Installation On Existing Pistol Dovetail No Batteries - No Switches - Always On- Always Ready