This impeller is designed to use with Waterway Hi-Flo Discharge series 1-1/2-Horsepower pool and spa pump. This has an extended inlet opening and at the shaft side there is small raised ring around the shaft the ring is 5/16-inch tall and has an outside diameter of 1-9/16-inch. This also has a small ridge around the outside diameter of the impeller on the shaft side. Available in gray color. Measures 3-2/3-inch length by 4/5-inch width.