TRUGLO Fiber-Optic Front and Rear Handgun Sights for Glock Pistols Fiber-optics for the BRIGHTEST AIMING POINTS even in low-light conditions TRI-DOT AIMING SYSTEM of contrasting front and rear colors CONCEALED FIBER cannot be seen by target; SNAG RESISTANT DESIGN fits standard holsters FORTRESS FINISH COATING provides a permanent protective coating for maximum protection Fits Glock 20, 21, 25, 28, 29, 30, 31, 32, 37, 40 and 41 (Excluding M.O.S models)