Twist UV's are designed with a rotating union in the body for flexibility of installation. Easily place the inlet + outlet in a position to fit your plumbing. Ultraviolet is a proven dependable and effective method of controlling algae and harmful bacteria without leaving any residuals in the water. Aqua Ultraviolet utilizes the highest quality components designed to work perfectly together to maximize kill rates and ensure ease of installation and maintenance. There is no need to by pass or adjust your water flow. Our units will perform at or above stated levels throughout the life of the lamp.