The Propane Kit is only available for the 4500Z Kubota Gas Engine. Included in this kit are the required components for the 4500Z to run on Liquid Propane (propane tanks not included). The Propane Kit can run up to two propane tanks, unless the tractor is equipped with a 3-point hitch. A simple switch on the dash of the tractor allows you to switch between gasoline or propane on the fly.