Theese mittens are generous in size, I own a pair in medium and one pair in x-small. I have measured them and the diffrence in size is minimal, opt for x-small if you dont have hand size above 10. Both will fit a pair of doublelayered wool mitts from Woolpower beneath, giving enough warmth for pretty harsh winter conditions. Theese are excellent if you encounter situations where you expose them to mild abrasion, where a thinner mitten would soon have holes on them. They are on the heavy side for ultralight weight backpacking, but they pack up small. worksmanship is excellent, seams are neatly taped. You could have theese in winter and opt for a thinner pair in summer, mostly because of increased exposion to abrasion winter time and the long cut and nice toggle locks on theese gloves. I use them for packrafting, bad weather conditions and for around camp work winter time.