The blade adapter kit is a genuine replacement for select walk-behind lawn mower models. The kit includes the blade adapter, hex cap screw, and bell blade support. Together, these components allow the blade to be seated securely under the mower deck and rotate to cut the grass. These parts are exposed to constant vibrations and may come into contact with the ground or other debris, which can lead to damage or wear over time. In the event that they fail, the blade will not securely attach to the mower and it will be unsafe to use until the hardware is replaced. This OEM kit can deliver the parts needed for the job. This genuine blade adapter kit is manufactured by MTD and is compatible with hundreds machines from this brand, as well as those from Troy-Bilt, Yard Machines, Yard Man, and Bolens. While replacing the adapter kit, it is a good idea to clean and sharpen the blade and clean under the mower deck. Always disconnect the spark plug and wear gloves for safety when working on the mower deck or engine parts.