This PLS 5 Watt Germicidal Compact Fluorescent lamp with a 2 Pin G23 base is a compact UVC (germicidal) bulb used in water and air disinfection units to aid with the deactivation of bacteria viruses and other micro-organisms. Offering saving of up to 80% in energy consumption this bulb also boasts an impressive 8000 hour lamp life. Common applications are pond filtering and disinfection of drinking water. Warning do not look directly at this light source as UVC radiation is harmful to the human eye.