This tool works on all Polaris Sportsman 400 (4 stroke only) and 500 models. Installs Polaris part number 3084837 water pump seal. This is our custom water pump seal driver. This particular seal is hard to install because using a socket will damage the thin outer surface of the water pump seal. It also wont allow a full seat because it fits in a slightly lowered machined pocket in the crankcase. Use a big rubber mallet to pound it in perfectly.