Swim-sters special needs swim diapers are perfect for anyone who requires a diaper while swimming. They are designed to be worn discreetly under a swimsuit and they are perfect for individuals with bowel incontinence. Testing results show that Swimsters effectively contain solids and help prevent harmful from entering the water. Sizing: XS-Size 6/8-Waist:17-24"; Weight: 40-58 pds. S-Size 8/10-Waist:18-27"; Weight: 59-74 pds. M-Size 10/12-Waist: 20-29"; Weight: 75-89 pds. L-Size 14/16-Waist: 21-32"; Weight: 90-118 pds. XL-Size 18/20-Waist: 22-34"; Weight: 119-141 pds.