We bought this costume for my 3 1/2 year old for Halloween.  He loves it!  It fits him perfectly and will probably will even fit next year since it is a little long.  The muscles are awesome and really completes the costume.  It even washes well.  The first time my son wore it he got grape juice right on the white part in the middle of the costume.  It washed right out.  He will be getting a lot of use out of this costume.  Great purchase!  The mask that comes with it is a little flimsy, but my son loves it.