It's a cute costume, but the quality is not very good.  It feels like a thinner version of felt.  It's true that the sizes run really small.  I bought the 2-4yr old size for my 22 month old and it fits him almost perfectly.  I can't imagine a 4-yr old fitting into it.  The back of the superman suit doesn't have a closure.  The cape is velcroed on to the suit to cover the opening in the back.  I guess for this age, this is good enough.  You can actually wear clothes underneath if it's cold outside.  I kind of wish the material wasn't as cheapy feeling.  I paid $[...] for it, but I think it should have been more like $[...] for the quality.  Oh well.