The GENERAC 7101 Battery Heater Kit is for 9-22kW Air Cooled Units that were manufactured from 2008 to the present. The pad rests under the battery to keep it warm under cold conditions. Not necessary if you are using an AGM style battery. It is important to note that the oil in the generator should be replaced with 5W-30 synthetic oil when installing any cold weather kit item. The 7101 Battery Heater Kit comes with a 1-year limited warranty.