Generic G20T10: Germicidal Lamp, T10, 20 watt, 58 volt, 5000 hour rated bulb with G13 base. Germicidal lamps are Low-Pressure Mercury-Arc lamps that emit radiation peaking at 253.7nm(UV-C). This output at 253.7nm is highly effective to inactive microorganisms such as algae, bacteria, virus, yeast and mold