The caliper is made of silver metal. Two tube arms that connected by a pin that serves as a pivot that allows the movement of the arms. Above the connection point, there is a screw whose rotation releases or closes a spring that allows the arms to open and close. A round metal body goes into the lower part of each arm, on one side of which is a point that sticks to the drawing surface, and on the other side one with lead and the other with a nail for writing in ink. In working mode, one arm will have a tip and the other a writing tool. The caliper was made in Japan.