Bobé PF-48-2 48" Pure Flow Stainless Steel Waterfall with 2" Lip Back Inlet - The Pure Flow waterfall is engineered to flow based on pressure. Constructed of marine grade stainless steel that is 1/8" and 1/4" thick, you will never again worry about warping or caving. The waterfall has an integrated mechanism that breaks up and slices debris to help prevent clogs. The Pure Flow waterfall is the next level of pool waterfall engineering.