A great tool for the precision resizing of holes in thin materials. Whenever I need to create a precision hole I use a standard drill bit to drill a pilot hole and then use a reamer to enlarge the hole until I get a good fit. In very thin materials you can skip the pilot hole and just use the reamer. Reamers cut cleaner holes than twist bits and do not have the tendency to rip very thin materials.
Works great in wood, plastics, composites and thin soft metals.