Tooshie Swimmers use the same patterns as regular OS and SM Tooshies. They are made using heavier PUL outer for durability and athletic wicking jersey inside that allows liquids to pass through, but not poo. Each layer has its own set of leg elastics to help keep solids where they belong. The PUL used for Swimmers is heavier to withstand concrete and sand.
This diaper comes in two sizes: LG which fits 10 - 45+ lbs and SM which fits 8 - 30+ lbs; but, since there are no soakers or inserts, it will likely fit larger sizes.
Make sure to add absorption if needed for the trip from home to the water or for times when not in the water. Use an insert or even a small towel.