GoodNites Size S/M Bedtime Pants fit boys 38-65 lb. (clothing sizes 4-8);The #1 NightTime Protection Brand*, with 5 Layer Protection *Youth Pant Category;NEW Marvel Iron Man designs (S/M only);Disposable, odor absorbing pants help protect pajamas and bedding;GoodNites Bedtime Pants are eligible for Flexible Spending Account (FSA) purchases