Truglo tritium pro starts with the brightness and durability of our original tritium night sights.All of our pro level features including an orange focus-lock ring for increased front sight contrast for even faster focus, angled rear sight edge for emergency one-hand operation, visibility in all shooting conditions 24/7, compact design maintains factory sight radius and fits standard holsters.Glows in the dark, no batteries or light exposure required fortress finish nitride protective coating.Assembled in the usa.Rear Color: GreenFrame Material: SteelFrame Color: Nitride FortressFirearm Fit: Glock 40 MOSStyle: 3-Dot High SetFront Material: TritiumRear Material: TritiumFront Color: Green with Orange OutlineFirearm Type: Handgun