One-piece, over-the-head. Fits most 50+ chests and 42+ waists. According to manufacturer, removing of wrinkles is very easy. First way is to remove costume from bag as far enough in advance from when you want to wear it, unfold and fluff the costume, and just let it hang on a hanger. You can also leave it in your bathroom while you shower to allow the steam to remove wrinkles. The best way is to use a steamer. This is the fastest and easiest.