The title says it all. The size states 4-6 but then contradicts itself and says for 3-4 year olds. Um......NO. If you have a large 3-4 year old then maybe, just maybe yes but in all actuality this is for a 6 year old. Definitely not for a 3-4 year old. Cool costume I just wish the size was what it says it was. Also the opening where your childs head goes through is awfully small for a normal head to go through. I like the costume and I will keep it for when it will actually fit him in 2 years but for now I have to buy the toddler size that says 1-2 year olds because that is for an average 3-4 year old. So the size was an issue but I still like it, just not for this year.