This is a genuine OEM replacement fuel cap sourced directly from the manufacturer. The fuel cap is used on lawn and garden engines that are powered by fuel. It is an integral part of the machine's fuel delivery system. Fuel caps prevent fuel from seeping out of the fuel tank and becoming a safety hazard. The cap's primary function is to keep fuel in the tank and keep water and other contaminants out of the fuel. Everyday use and outdoor elements can cause deterioration of the fuel cap. During scheduled maintenance and refueling of the tank, a visual inspection can quickly show any damage that needs to be addressed. The fuel cap cannot be repaired; it is a one-piece molded-plastic component that must be replaced when necessary. Tools are not required to replace the fuel cap. Work gloves should be worn when working with fuel. Unscrew the broken fuel cap and remove it from the fuel tank. Screw the new filler cap in place. Make sure the threads are lined up and the fit is tight.This fuel cap is sold as an individual unit. It is compatible with fuel tanks on lawn mowers, tillers, generators, and other engines manufactured by Tecumseh, Craftsman, Toro, and Briggs & Stratton.