All of our Tune Up Kits include Original Equipment Manufacturer (OEM) parts to perform a simple tune up. Toro TimeCutter Series Tune Up kit includes air filter, fuel filter, oil filter, spark plugs, oil and a set of new blades. All parts are Genuine Toro and NGK. Nothing in this kit is aftermarket. The oil specially formulated for Toro Twin Cylinder engines. This custom kit fits models: 74657 (TimeCutter ZS 4200T), 74675 (TimeCutter SW 4200), 74723 (TimeCutter SS 4250), 74760 (TimeCutter MX 4250), 74784 (TimeCutter SW 4200), 74787 (TimeCutter SWX 4250)