Wouldn't stay up
I am only giving 2 stars because these would not stay up on my legs. My thigh measures at 20" and I ordered a large based on the chart. The warmers fit snuggly without being too tight, so I believe they were the correct size for me, but without trying a  larger size I guess I won't know for sure. There is very little grippy material though and they worked their way down quite quickly while riding, and even walking around in doors. The quality of the knee warmer seems quite good and I wouldn't have concerns over durability if they stayed up, but since they don't [for me] I can't use them and am not willing to risk a second purchase of a different size. (I didn't feel right returning them since I did ride outside with them)
Rating: 2 stars