According to the chart on the packaging I bought the recommended Small for corresponding shoe size 6-7. when I came to use they didnt fit well for my 6.5 shoe i have. I'd recommend others need at least one size up for best fit.

I have size 43 5.10 shoes so at the lower end of size L, and while I can get the overshoes more or less in place the zip base is too stretched to do up. There is no easy way to get at the laces with the overshoes on so you have to take them at least mostly off to adjust laces or remove your shoes. The build around the toe looks excellent and the overall construction looks up to the job, but if it takes me 10 minutes to put them on and I can't leave them in place and get at the laces they're pretty much unusable, so I'll be sending them back.

Brought an XXL for a 10.5 size shoe, nearly impossible to fit and definitely impossible to zip up, would avoid if you have a shoe size above a 9 and you want to be able to use them.

These are not waterproof although they keep the wind out and are ok on muddy trails but fail in moderate downpours I was very disappointed to have wet feet. These went over my mtb flat shoes and because of the sizing is not accurate I struggled to get them over. For this price point I would not purchase these again.