So I ordered the 141 mm size in pink after measuring pairs of sunglasses that I own and after reading reviews. I like to think that my head is an average size for a woman. If I hadn't ordered the 141 mm size, there's NO way these would have fit me. Any smaller and they only would fit a 6 year old. I don't know why the manufacturer/company thinks so many people have such tiny heads. The product itself is quite good. I've had them for about a week and have used them for biking and walking in hot, humid August weather in NH. They do not fog up, as was the case with other brands I've tried. I like the color and I like that they came with a decent case. The only reason I gave them 4 stars and not 5 is because of the sizing. They just fit. They are not too tight and I don't feel like I will lose them doing active sports. Next tests will be paddle-boarding and zip-lining.