From Manufacturer
Specifically designed for your Ruger LC 9 pistol to help you get on target quickly and intuitively, the MEPROLIGHT Fiber Optic/Tritium Bull's-Eye Rear Pistol Sight features a simple aiming system that doesn't require a separate front sight. To get on target, just bring the center dot into the middle of the outer circle (making the familiar bull's-eye pattern) and fire. Its battery-free green fiber-optic and tritium illumination is suitable for all conditions—day or night. The fiber optic illuminates during the day using the available ambient light, and when there isn't any light at night, its tritium-coated pattern glows for you to see. Both types of illumination are "always on," so there are no switches to fumble with and no batteries to change, ever. Made of lightweight and durable aluminum with a low profile, it is designed to install easily on your pistol's slide and will fit most holsters.