Keep your mower running like new, season after season. Kit is designed for Toro lawn mowers with Briggs & Stratton EXi 163cc engine and serial number of 400000000 or greater. Includes 18 oz. bottle of 4-cycle engine oil (part # 38916), one spark plug (part # 130-8167), one air filter (part # 130-8165) and a .05 oz. packet of fuel stabilizer (part # 130-2393). If your mower serial number is 316999999 or lower, you will need kit # 20234.