I bought these gaitors mostly for fat biking to keep the snow out of my boots. Originally I ordered the S/M but they would not fit around my snow boot. I am a EU 40 or ladies 7.5/8. Was a bit surprised this would be considered a large/xlarge. Anyways a bit of a bummer to have to send the ones back that were too small. Today was my first jaunt out using the gaitors - they look good, maybe a tad large around the front of the boot but they worked well and kept the snow out of my boots. Would have rated 5 stars but they pop off of the from boot clip pretty easy, will try clipping them in more aggressively my next trip out. At any rate, once you get your sizing figured out, I would for sure recommend them!