LSE Lighting LSE-40WUVCT5Base CNZT5L75 UV-C Germicidal Ultraviolet Replacement Bulb, 40W Non-chemical approach to disinfection, bulb is 15-millimeter wide, 33.50 inch in length and fits the t5 base At least 16, 000 microwatt seconds per square centimeter but many units actually have a much higher dosage Commonly found in pond, pool and aquarium equipment 8, 000 hours or more of normal usage Keeps water clean and "green free"