When Truglo TFX PRO sights immediately took off and gained critical acclaim, Truglo noticed that the world of TRITIUM night sights needed a similar upgrade. Starting with the brightness and durability of their original TRITIUM night sights, Truglo added all of their PRO level features, now including an orange FOCUS-LOCK ring for increased front sight contrast. Front sight FOCUS-LOCK ring for even faster focus Angled rear sight edge for emergency one - hand operation Unmatched visibility in all shooting conditions 24/7 Compact design maintains factory sight radius Assembled in USA with quality Swiss tritium for maximum brightness Glows in the dark - no batteries or light exposure required FORTRESS FINISH nitride protective coating Fits standard holsters Glock 42/43/43x/48