Naturallighting.com - Germicidal Ultraviolet Lamps T5, T8, T10 Germicidal Ultraviolet T10 Lamp, G20T10, 20 Watt, 24 Inch, Bi Pin, 10,000 hour average useful life. Primary use for these lamps is sterilization of air and the surfaces of various materials and water or liquid. WARNING - The radiation output of these lamps is harmful to eyes and skin and can cause damage. Protect your eyes and skin against the ultraviolet rays. Price listed is per bulb. Call or email for case qty pricing.