Goniometers are effective tools to help measure digits and joints. Determine joint axis and range of motion by using the goniometer. The linear measurements are in both inches or centimeters. It has three scales which read 0 degrees to 90 degrees, 0 degrees to 180 degrees, and 0 degrees to 360 degrees in 1 degree increments. The 12 1/2 inch International Standard Goniometer is an economical transparent plastic instrument that is latex free.