Maybe you already have that wrench. Have you looked for the stock tool kit? The spark plug wrench is the tubular piece with smaller holes driller in the ends to fit the "Tommy Bar". A BMW bike tool kit is in a cloth or vinyl roll. It is often kept in the "tool box" under the seat. Or maybe your bike has the tool compartment in the rear of the seat? Like Wrangler says if you really need one then get the stock kit. Good to have a few tools with you on these bikes.