I have a Walmart Brute 675EX lawnmower (Product #961480037 02, Model #30534379). The key fits perfectly, and my lawnmower now starts with a single simple pull....no more pulling the cord 10 to 20 times to get it started. If you hit something that you shouldn't have (a rock, or in my case a rebar), there is a good chance your flywheel key is broken. Word of caution, you will need a 15/16 inch socket to get access to the flywheel key, which is not common in a normal socket set. So buying the replacement key is one thing, but buying extra tools to replace the key is another story.