TRUGLO Tritium Pro Sight, Fits Glock 17,17L,19,22,23,24,26,27,33,34,35,38,39, Large White Focus-Lock Ring on Front Sight & U-Notch Rear Sight, White Dots in Light & Green Dots at Night TG-TG231G1W Simply put" TRUGLO(R) manufactures bright ideas. When TFX(TM) PRO sights immediately took off and gained critical acclaim" they noticed that the world of TRITIUM night sights needed a similar upgrade. Starting with the brightness and durability of their original TRITIUM night sights" they added all of their PRO level features to give you the advantage when you need it the most.