unacoo kids 2-pack or 3-pack cotton with spandex long sleeve turtleneck t-shirt for girls (age 3-12 years)(purple+off+dull red, xs) unacoo according to customer's feedback, these turtleneck shirts run a little small. so we suggest that: if your baby is 2-3 years old, please choose size xs. 4-5 years old girls choose size s; 6-7 years old girls choose size m; 8-9 years old girls choose size l; 10-11 years old girls choose size xl. about the size details, please see the products pictures on the left side.