When it comes to tritium gun sights, aluminum sleeves and painted-on white rings are the norm. Night Fision breaks the mold, literally. Our patented, injection molded sleeve design not only holds our tritium vials securely in place, it creates a brighter and more durable ring, we call The Perfect Dot, that provides maximum visibility both day and night. On our Glow Dome front sights, the ring carries phosphorescent material aiding in a front sight that aids visibility while your eyesight adjust to dark light. Front Sight Width: 0.14". Front Sight Height: 0.213". Rear Sight Height: 0.272". Fits: Glock models 20/21/29/30/36/40/41, including S and SF variants.