[SIZE OF CALIPER SET]Our wing divider are made from high quality carbon steel. Package included 4 inch compass, 6 inch compass and 8 inch compass. 3 sizes are available to meet your every need. [RUST PROOF] We use Carbon steel material to make woodturning calipers to that wing divider compass can work longer without and rust [DESIGN]The divider caliper is great for gauging the diameter of an opening and then transferring that measurement to a ruler. [DIVIDER CALIPER]A useful dividers tool for uneven surfaces, great for drawing arcs, circles, making outlines, line segments, dimensioning, protractors, dividing lines, edge marking, etc. Widely used in leatherworking, woodwork, metalwork and other drawing work. [Adjustable Width]The steel legs feature hardened points for precise marking of the work piece, precise fine adjustment due to solid nut. Works perfect for wood turning lathe projects. Material:Carbon steel Colour:As Shown Package Contents: 3x Leather Compass Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.