Size S Length: 40CM UP Circumference: 29CM Down Circumference: 20CM Small size is only for little teenagers. Please choose it carefully, otherwise, the knee pad will be tight for you or your Child.
Size M Length: 42CM UP Circumference: 32CM Down Circumference: 22CM
Size L Length: 44CM UP Circumference: 36CM Down Circumference: 24CM
Size XL Length: 46CM UP Circumference: 40CM Down Circumference: 26CM
NOTE: It is manual measurement, there may be 1-3cm error. And item color displayed in photos may be showing slightly different on your computer monitor since monitors are not calibrated same. Hope you will be understanding.