It's a headache pressure reliever. The doctor puts it on and wrenches it down real tight. Then after about ten minutes he loosens it and says, "Does that feel better?".
Previous TD had it in the shop because the director gave him lots of headaches, obviously.
looks like the thing my dentist uses for a big silver filling - though his is more for dinosaur sized teeth. Think I've seen them in James Bond movies as well.
Its called a belt oil filter wrench. There are three main types: belt, chain, and strap. I believe they were more popular in Britain than in the states. I have only seen them a couple of times over the years. Mainly by motorcycle mechanics for some reason.