ITEM NAME:6'' 150mm Set of 3, Inside, Outside and Divider Spring Caliper Sets Description: This item includes a Inside Joint Caliper, a Outside Joint Caliper and a Spring Divider both of same capacity. A transfer measuring tool, does not have a graduation scale. Bow spring ensures uniform tension over working range with centrally mounted quick release adjusting nut. Precise measurement: with fine screw adjustment and quick slide action. Made of high-strength carbon steel, durable in use. Specification: Material: Carbon Steel Capacity (the max dimensions can be measured): 150mm/ 6inch; 200mm/ 8inch; 250mm/ 10inch; 300mm/11.81inch Thickness: Approx. 3mm/0.12inch Package Includes: 1 Piece Internal Spring Caliper 1 Piece External Spring Caliper 1 Piece Spring Divider.1 Piece Spring Divider. 1 Piece External Spring Caliper. 1 Piece Internal Spring Caliper. Bow spring ensures uniform tension over working range with centrally mounted quick release adjusting nut.