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. Front Sight Width: 0.14". Front Sight Height: 0.44". Rear Sight Height: 0.476". Fits: Glock Suppressor Height 17/17L/19/22/23/24/25/26/27/28/31/32/33/34/35/37/38/39/20/ 21/29/30/36/40/41.