S: Thigh circumference 29-32cm, joint circumference 17-20cm, foot circumference 13-16cm, leg length 25cm.M: Thigh circumference 36-39cm, joint circumference 22-25cm, foot circumference 16-19cm, leg length 30cm.L: Thigh circumference 43-46cm, joint circumference 27-30cm, foot circumference 19-22cm, leg length 35cm.360 SUPPORT: the light compression guarantees stability and improves balance among the muscle groups for a full support and avoids injuries from turning into more serious conditions. Look at our VIDEO and measure based on our instructions to select the correct size. You can find the size chart in the images.PAIN RELIEF: reduces pain caused by cruciate ligament injuries, osteoarthritis and kneecap problems by increasing the joint& 39;s temperature helping to reduce the inflammation.FAST RECOVERY: optimal joint temperature increases blood circulation, improves Oxygene delivery, increases performance for a faster recovery.VETERINARIAN PREMIUM QUALITY: our knee brace is designed and manufactured to provide superior support and comfort without compromising the dog& 39;s mobility. The High Performance Neoprene offers enhanced elasticity for a better adaptation to the dog leg. Some dogs have a fallen hip and the upper belt may slide back and fall off.NEED A STRONGER SUPPORT The Knee Brace is made of a 2 mm neoprene and it is totally flexible. Gives a light compression, increases the blood circulation making the recovery process faster."