I love these knee warmers bought a pair for my wife too. They are so light, comfortable, and effective when the temperature is above 45. Another good quality is that they never slide down the double grippers are amazing.
the knee sleeves are very wicking, lightweight and way better than sunscreen. i ordered the size medium. the gripper elastic at the top is a bit tight for my 19 thighs but definitely not unbearable. i wear them under my shorts and they have no problem with slippage. the length is perfect. i use these on rides that i wear my compression knee socks and the combo makes a perfect cover for sun protection. i like the white color for extra coolness as compared to the black, but the white ones show the dirt etc. they clean up just fine though.