Product details:

They feature a stamped steel impeller that provides optimum water flow, while consuming less horsepower than stock pumps. The impeller also limits high rpm cavitation (air in the water) and will not crack, corrode, or fatigue like aluminum impellers can. The Action Plus pumps also feature a heavy-duty shaft, bearing, and seal. Action Plus aluminum pumps weigh approximately 30 to 50 percent less than stock iron pumps, and have an exclusive counterbore to keep the bearing from "walking" in the housing.