4pc Set. To locate work edges shoulders, grooves, center points, and scribed lines for accurate machining such as jig boring, etc. All parts hardened and ground. Includes: .200" x 3/8" Edge Finder, .500" x 1/2" Edge Finder, .200" & .500" x 1/2" Edge Finder, .200" & Pointed Contact x 1/2" Dia. Edge & Center Finder.