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.