This is an automotive metal blade fuse. It is an electrical safety device that operates to provide overcurrent protection to a vehicle's equipment and wiring. Its essential component is a zinc wire that melts when too much current flows through it. The contact point is built from metal alloy for better performance. It is manufactured for circuits that operate below 32V at 20A current. Since the fiberglass body is clear, you can easily determine whether the fuse is blown or not. It is easy to install and easy to replaceable fuse.