I want to give these 5 stars, but I just can't. I have three--one of each color--and it's clear they're mass produced because the sizing varies greatly. I ordered smalls (I'm normally a 34 B or C). One fits great, and the other two are too big. Primarily, the straps are just too long. Plus, they stretch as you wear them, so they just get looser. Then you sit down to pump, and the straps sit limply on your shoulders, resulting in a loose hold on the flanges. It's not terrible, but I have to prop them up with a pillow to keep them from sliding down and losing suction. If the straps were adjustable, they'd be perfect.