XS Sights XS Big Do Tritium Night Sights, Front Sight Only, Tritium Center and Orange Outline, Fits Remington 870 Shotgun with 0.125-0.140 Diameter Bead SG-2004-3N XS Tritium Night Sights offer the best front sight visibility in all lighting conditions" combining tritium with XS' patent pending glow dot. Upgrade a home-defense shotgun to a high-contrast front sight that absorbs light and glows in less than ideal conditions. Optic Orange is designed to offer a high-contrast sight picture when shooting in bright light conditions and maintain its visibility in decreasing light levels. To ensure visibility in low light when uncharged" optic orange is primarily based on yellow with a hint of red. The increased surface area of the convex dot increases light absorption" intensifying the charge of the glow properties of the dot.