I was looking for warmer socks for my 3.5 year old son for the Seattle winter (around 35-50F). I bought a set and I really liked the warmth and thickness of these socks. My son loves them too. They keep his feet warm, especially when he's wearing rubber boots. I've noticed that they may have shrunk a bit after washing and drying 2-3 times which actually worked great for us as I got the size for a 4-7 year old and they're just a little bigger now are for my son. They stretch well and seem durable to me. I just bought another change set as my son just picked them to wear.