According to the brand, the Happy Nappy is the most advanced reusable swim nappy in the world, incorporating the famous Happy Nappy™ technology. Multiplied award winning reusable swim nappy, approved and recommended by swim schools. Replaces disposable swim nappies, meaning less waste in landfill. Inner lining is extremely gentle on babies' skin, made from neoprene for comfort, durability, practicality, warmth and sun protection. Size stated Small or 0-3 months.