Big Horn 19053C 3 Pieces 8-Inch Spring Caliper / Divider Set Big Horn outside calipers is a useful measurement transfer tool when working with round stock or oddly shaped materials and then transferring that measurement to a ruler Big Horn inside calipers are great for gauging the inner diameter of an opening and then transferring that measurement to a ruler Big Horn flat leg dividers is a useful measurement transfer tool for uneven surfaces; Also great for a variety of uses such as tracing contours and scribing circles into metal Hardened and tempered bow springs and fulcrum spools assure uniform tension without side play while using this caliper set The forged steel legs feature hardened points for precise marking of the work piece | An adjusting screw has a self-seating washer and nut to permit quick and positive adjustment