The purpose of the Impeller, is to propel air, and often other materials like snow or leaves, into or out of your equipment. For snow throwers, the speed of the impeller may increase or decrease the flow of snow. In 2-stage snow throwers, a high-speed impeller helps move the snow from the initial point of collection by the auger through to the discharge chute. Impellers can become damaged over time from regular use. To ensure safe operation, purchase your replacement impeller from an OEM parts dealer.