Features： 1、Aid in Treatment: Aid in physical therapy by determining the range of motion of the joint, which is an easy way to measure recovery after surgery. 2、Easy to Observe: The limb angle ruler can directly place the device on joints or limbs for easy observation. 3、High Accuracy: The joint motion goniometer has high measurement accuracy, small error and convenient to use. 4、Battery Powered: The plastic joint angle finder is made of high quality plastic material, durable and battery powered. 5、Uses: Protractors are suitable for those who are at work or who are undergoing physical therapy, sports therapy, or post operative rehabilitation programs. Specification： Item Type: Finger Goniometer Material: Plastic Battery: 1 x Button Battery (Not Included) Battery Model: CR2032 Resolution: 0.1 Degree Accuracy: ±1 Degree Measuring Range: 0-180 Degree Package List： 1 x Finger Goniometer