The Trijicon Bright & Tough Night Sights Model 600689 are three-dot iron sights designed to increase night-fire shooting accuracy by as much as five times over conventional sights. These suppressor/optic height sights feature green tritium-phosphor lamps with white outline rings for enhanced visibility.Trijicon Model 600689 Suppressor Height Night SightsGreen tritium-phosphor lamps with white outline ringsSapphire window for durability and claritySilicone rubber cushion and protective aluminum cylindersNo batteries required - self-illuminating tritium technologyCompatible with Glock 20/21 large frame 10mm modelsFunctions as backup iron sights with suppressor or optic setupsPerfect for tactical applications concealed carry and low-light shooting scenarios where reliable sight acquisition is critical. The suppressor height design ensures proper sight picture even when using suppressors or red dot optics.