Night Fision night sights carry more tritium than the average night sight on the market and a domed lens engineered to create the a crisp, defined glow. 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. The domed lens collimates tritium rays for a sharper sight picture. CNC Machined out of high quality steel. Black Nitride coating used to improve wear and corrosion resistance. Gunsmith recommended for installation. Front Sight Width: 0.140″. Front Sight Height: 0.213″. Rear Sight Height: 0.272″. Compatible w/Glock models 20/21/29/30/36/40/41, including S and SF variants.