AmeriGlo "Ghost Ring" night sights are great for quick target acquisition. The serrated rear sight has two lamps aligned horizontally and is secured with twin clamping screws. AmeriGlo Glock night sights feature Betalight tritium lamps. These lamps, secured in a white PVC sleeve which provides permanent white daylight rings, are housed in metal sights. AmeriGlo Glock night sights aid the shooter in quick target acquisition during low-light conditions. The lamps require no power or light source for illumination. All AmeriGlo Glock night sights carry a 12 year warranty on the illumination. The AmeriGlo +0 Ghost Ring 3 Dot Glock Night Sight set fits Glock models 20 21 29 30 31 32 33 36.