TRUGLO TFX Tritium and Fiber-Optic Xtreme Handgun Sights for Smith & Wesson Pistols UNMATCHED VISIBILITY in all shooting conditions, night or day; GLOWS IN THE DARKno batteries or light exposure required Front sight FOCUS-LOCK RING for even faster focus FX SEALED CAPSULE DESIGN provides maximum protection and durability; FORTRESS FINISH provides a permanent protective coating; Impervious to oils, chemicals, cleaning solvents, and ultra-sonic cleaning processes CONCEALED FIBER cannot be seen by target; SNAG RESISTANT DESIGN fits standard holsters Fits Smith & Wesson M&P (including SHIELD and .22 models, excluding .22 Compact / C.O.R.E. models), SD9 and SD40 (excluding VE models)