Shoot better day and night. Xs F8 night sights increase front sight focus by using a large, high-contrast front sight for fast sight acquisition. The wide notch rear sight easily aligns with the front sight and increases front sight visibility. Xs F8 night sights give you the best notch and post solution for fast sight acquisition in all lighting conditions. Features and benefits:- tritium powered front and rear: glows in low light to aid in sight alignment- colored front sight ring: highly visible orange ring designed for maximum visibility in bright to low light levels- photoluminescent ring: photoluminescent particles absorb ambient light and glow in low light- rounded base notch: draws focus to top edges of sight for proper alignment- rear sight overhang: reduces glare from rear sight in bright daylight for greater sight definition- rear sight ledge: aids in one-handed slide manipulations- easy installation: easily install by hand or sight Pusher tool- wide rear sight gap: increases the amount of light around the front sight for greater visibility in low light- figure 8 sight picture: fool proof alignment prevents shooters from mixing up the front and rear sight Specifications:- fits: Glock 20, 21, 29, 30, 30S, 37, and 41".