My 4 year old loves this costume. It is really good quality, much better than other Batman costumes on the market. It comes with a cape with an attached head piece and also a detachable plastic belt which my son loves. The blue arm bands and the blue boot tops are attached -- which I found nice so as there were less items to misplace. I got this in a size small and there is plenty of room to grow. I'd say an average-sized 6 year old and a smallish seven year old would be able to fit in this costume without a problem.