Flap Happy- navy swim shorts $22.00 size ---- XS-10-15lbs. M-20-25lbs. L-25-30lbs.-SOLD OUT XL-30-35lbs.-SOLD OUT XXL-35-40lbs. Flap Happy nylon navy swim shorts with built in swim diaper. The liner is 100% cotton with polyurethane and the short is 100% nylon. Related Items Here are some products that may also be of interest to you: