RESUN U.V. STERILIZER system sterilizes the water that passes through it, killing algae and pathogenic bacteria. - Patented design that effectively prevents the glass tube from being damaged by anything that comes along with the water flow. - Has spiral innovative design, allows water spends more time inside the unit for better results. - Safe and reliable, upon opening the systems automatically turns off the light for safety. - Has a signal light for lamp operation. - Wide range from 5W to 55W. Designed and produced according to high safety standards.