The Hayward Vari-Flo XL control valve SP0710XALL is made of PermaGlass XL, which is an exclusive material by Hayward. This valve is designed to provide maximum flow and has a lever action handle that makes it easy to use. With this handle, you can choose from six different valve/filter functions, including filter, backwash, waste, rinse, closed, or recirculate. Additionally, it comes with an integral sight glass that lets you know when the backwashing cycle is complete.