Purely Products PUVLF500 40-Watt UV-C Germicidal Ultraviolet Replacement bulb Non-Chemical approach to disinfection; Bulb is 15-millimeter wide, 20.00-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 laboratories, hospitals and clinics to sterilize surgical equipment 8,000 hours or more of normal usage Prevents DNA of germs to reproduce