Compatible Models: The VIQUA 602807 UV Lamp is for use in the F, F+, F4, F4+, F4-V, F4-V+, Plus Pro15, UVMax-47, 650686, 650687, 650640-R, 660041-R, and 660044-R ultraviolet water systems | Reliable Disinfection: Provides protection from microbial contaminants, including protozoan cysts, bacteria and viruses. During ultraviolet disinfection, the water is exposed at a controlled rate to UV light waves, which deactivate the DNA of microorganisms, preventing them from reproducing. | Long Lasting - Low Maintenance: VIQUA high output mercury vapor lamps offer reliability and stability giving off the most amount of UV intensity in a compact design. The high output mercury lamps that are used in the Viqua systems have a one year life. After a year, UV light weakens and isn't strong enough to properly treat your water. Replacing your lamp annually with a genuine VIQUA lamp ensures optimal system performance. | Trusted Brand: This is a genuine VIQUA replacement part. | Safety Note: NEVER look directly at the UV lamp when it is powered on. Ultraviolet light is harmful and dangerous to your eyes and skin. Follow the instructions carefully to avoid injury.