Name: Ruler :3pcs Brand new Characteristic: of coverage in 1 degree increments to the accuracy of the (international measurement standards). The measurements in inches and centimeters are on the arms. The transparent plastic allows the observation of the axis of movement and range of movement of the Board. Precision and Comfortable to wear and carry. Durable in use colour:Photo Color Material:plastic Size: 100mm, 200mm, 300mm Package Contents: 3*Goniometer(1pcs for each size ,100mm,200mm,300mm) Only the above package content, other products are not included. Note: Light 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.