The Starrett 827 Edge Finder is for fast, accurate work location. Work surfaces may be located easily, quickly and accurately with these edge finders. Work with flat, straight edges, shoulders, grooves, round work, studs, dowels or center points and scribed lines – all can be accurately located with this handy tool. Body and contacts are made of tool steel, hardened, ground and lapped to close tolerances for diameter and concentricity. Single End, 10mm Body Dia., 6mm Contact Dia. concentricity.