HushGecko Kids Thermal Swimsuit, UPF50+ Protection, Neoprene Swimwear 3mm Thickness, Swim Suit Wetsuit Aqua Warmer For size selection, please refer to the Size Chart in the product pictures. NOTE: Item tends to run small. If you are not sure, recommend buying one size up. Inner side is 100% Neoprene, keep your child warm in water. Thickness is 3mm. UV50+ protection from the sun's harmful UVA and UVB rays Provides added warmth and extra water buoyancy. Comfortable and flexible material fabric offers optimum mobility Front zip closure with Velcro tab for easy on and off Great for the Beach, Lake or Pool and excellent for learning to swim or for extended periods in and around the water