The quality of this is incredible! Just thick enough for good warmth in rainy cold Washington & it is adorable on! I would just recommend sizing up one, my son is 5.5 months old, weighs 17.5lbs, I ordered him the 6-12 month thinking it would fit him through the winter but it’s snug and fits NOW. So I’m sure he will be out of it quick! I would’ve ordered him a 12-18 & I’m sure it would’ve been exactly what I wanted.