The metal screw attaches to the muff guard bracket. It is a genuine replacement part sourced from the original manufacturer for use with blowers, engines, generators, pressure washers, snowblowers, and vacuums made by Briggs & Stratton, Toro, and Lawn Boy. This item is available as an individual replacement part. When replacing this screw a wrench will be needed. It will need to be replaced if it strips or breaks.