Prevents embarrassing pool accidents. Many public swimming pools now recommend, or even have a rule, that these be used for hygienic reasons. Organic cotton fabric pant is made from tightly knit material. Lightweight and comfortable when wet, unlike disposable diapers, which are very heavy! And they keep your child cool and comfortable in the wading pool in the summer--why run around in the hot sun in a sticky plastic pool diaper? Wear alone or under a swimsuit. These do NOT require another diaper underneath. Sizes: S(13-18 lbs.), M (18-22 lbs.), L (22-25 lbs), XL (25-30 lbs), SL (30-37 lbs).