Considering that I have never used any product like this before, due to the fact that I have lived in the tropics all my life and do not usually get sunburn, I bought these because I am now starting to feel the effects of too much sun exposure. I do a lot of driving and my forearms would tingle and burn when in the sun for hours. So instead of changing all my shirts to long sleeved ones I decided to try these. First I had to figure out which end was the top, so I decided this had to do with the direction of the writing on it. When you put these on they actually feel cold, and the coldness stays for the entire time you wear them. If you have large arms like I do, the top will be a rather tight fit but they definitely will not roll down. They helped quite a bit but I think that probably the UV protection diminishes with the degree of stretching of the fabric to fit ones arm. I am sure someone with a smaller arm size than me will have more UV protection from them since they will not have to stretch as much and therefore will be thicker. The pale bluish colour also works with most of my shirts. All in, a good buy especially for women with larger than average arms.