This red push key can be used as a replacement in a range of lawn mowers. The user will push this key to start the mower's engine, so they can then mow the lawn. If the push key is broken or damaged, it could make it more difficult to start the mower. In some cases, the mower might not start at all.The key is made from plastic and is made to last and withstand the elements. However, there is the potential that it could become damaged or worn over time. It could crack or break, which would reduce its effectiveness. If any of these issues are present, the owner should replace it as soon as possible.The push key is for use with a range of lawn mower models from MTD, Yard-Man, Craftsman, and Troy-Bilt. This is a genuine OEM replacement part that is sourced from the manufacturer. It is sold individually.