Absolutely love these socks and the mary janes and ballet style too. Our baby has been wearing them since birth and is two months old now. They do slip a little once in a while, but are by far the best at staying on. We don't use any of the other socks at all, except for mary jane tights from Old Navy and Gap. These are a must and fit up to a year old! It's better than buying shoes that may interfere with baby foot growth. Also makes it easy to get dressed too.