Samson quick flip up sight bases are constructed from aluminum, have stainless steel clamps, and are hard coat anodized. With milspec dimensions, the sights lock into position and attach to any 1913 Picatinny rail. Front sight features XS Tritium Stripe front: 0.105" wide front post with vertical tritium stripe and white painted outline for visibility in any light. Rear sight features XS CSAT same plane aperture. CQB situations made easy with notch providing a 7 yard zero, aperture a 100 yard zero, or flip to the large battle aperture, all while maintaining zero. Mfg: Xs Sight Systems