Made of super light, breathable spandex, Medela's Maternity Support provides maximum comfort and relief for expectant moms. Helps ease back pain and provides abdominal support. Gently lifts mom's tummy to reduce pressure on bladder. Comfortable against the skin. Smooth and invisible under clothing. Size S/M = 23-27; pre-pregnancy waist, Size L/XL = 28-34 pre-pregnancy waist.