Designed by Dalhart Windberg and crafted of aluminum, the Windberg Artists Caliper is ideal for the indoor artist as well as the Plein Air adventurer. Measuring at 8 ½ in, the Windberg Caliper is designed to help an artist gain correct perspective of a subject and rotates 360 degrees for any angle. For example, when drawing the standing figure, use the points of the Caliper to measure the head, then count how many heads the height of the body is, how many heads an arm is, the legs are, etc. The Caliper is also handy for transferring the angles of subjects to your drawing surface.. The Windberg Artists Caliper is often used in the Windberg Art Center Workshops that Dalhart and his son Mike Windberg teach and you will not find another tool as affordable in the market today. The Windberg Caliper is simple but very useful tool made by hand in Georgetown, Texas.