Ratchet ring combination spanner set 10mm to 15mm, with Bi-Hex (12pt) ratchet ring. The 72-tooth ratchet mechanism means that just 5° of movement is required, allowing fasteners to be turned quicker and making them ideal for use in confined areas. They are manufactured from tough durable chrome vanadium steel with a with chrome plated finish and are supplied in a storage case that can be hung on the workshop wall or laid flat in a toolbox drawer.