Important reminder for Viqua UV system owners! To keep your water safely disinfected, the UV lamp needs to be replaced every year (or as recommended, often 12-24 months). This is the genuine Viqua S810RL replacement UV lamp, designed for the Viqua S8Q-PA, S8Q, and S8Q-Gold whole-house ultraviolet water treatment systems. It's also compatible with the older Sterilight SSM-37 system. This lamp is the heart of your system – it produces the UV-C light that zaps over 99.99% of harmful bacteria, viruses (like E. coli and Cryptosporidium), and other microorganisms as water flows through the chamber, without adding any chemicals to your water. It's an 8-gallon-per-minute (GPM) rated lamp. Installation is straightforward – just remember to turn off the power to the unit first! Using a fresh lamp ensures your family continues to have safe, clean water for drinking, cooking, and bathing. Don't wait for your old lamp to burn out; change it on schedule for peace of mind.