I got this product for my son. He is 8 months old and a little small for his age at only 17 lbs. He is still wearing some of his 6 month pants. I order several 6-12 months and they are too small. I put it on him and the zipper broke instantly. Good thing I thought they were so cute I order 12-18 months which is a little too big, but he will grow into it. I figure in 3 months they will fit perfectly. BTW even though it is a little big on him I still let him wear it. I like it.