This jumpsuit is 100% polyester. It has stuffing in chest area and upper arms to appear to be muscles. It has a back opening with Velcro closure. In good condition except for a small “pull” at end of right sleeve, which does not compromise the integrity of the costume. Size medium (7-8) . Approximate measurements for sizing are as follows: armpit to armpit=13″, neck to crotch=19″,sleeve inseam=13″ and leg inseam=22 1/2″.