he National Geographic Snorkeler Tuna 44 Kids Set (Yellow/Black 4XS 9-13) is your key to unlocking the adventures of the underwater world. The Tuna mask has two front CE Tempered lenses which gives a great field of vision, made from 100% Hypoallergenic Silicone Rubber with a lightweight Delrin Plastic Frame, and adjustable silicone rubber head strap for maximum comfort and fit. Mask has a feathered edge skirt for a great seal, with Ratchet Quick Lock strap adjustment. The Tuna Snorkel has an Orthodontic Mouthpiece for extreme comfort. Snorkel is equipped with easy mount snorkel keeper, and large bore tube for easy air displacement. Fin is constructed of three different materials to achieve the appropriate thrust-to-energy exertion ratio. This composite design maximizes snap and flex of the blade. Soft and comfortable foot pocket with adjustable open heel allows use of the fin for extended periods of time with or without additional foot protection. Fin straps are replaceable, and are equipped with Ratchet Quick Lock (RQL) buckles.