Item Type: Joint Ruler Material: Plastic Size: Approx.21.5 x 5cm / 8.46 x 1.97in Package List 1 x Joint Ruler 1Midlayer Printing: The joint measuring ruler adopts middle layer printing technology, and the scale will not be worn out due to long term use. 2Clear Reading: The transparent ruler permits observation of the joint's axes of motion and range of motion, you can to place the device directly on a joint or limb for easy observation. 3Multiple Use: Joint ruler is designed to measure angles of joints, range of motion of limbs and joints of the body like hip elbow and knee joints. 4Widely Apply: Physical angle protractor ruler which can be applied for measuring the range of joint motion and the angle of the spine, etc. 5Excellent Material: Spinal goniometer is made of plastic material, which has tough and sturdy properties. You can use this ruler for a long time.