The fabulous Swim Fin is an innovative children's swim float in the shape of a shark fin. It is worn high on the back which "suspends" children in the water so that they will not tip forward. This excellent kids buoyancy aid gives children a safe & secure feeling when they are learning to swim & it gives maximum support when it is submerged (ie. when children are vertical in the water doing doggy paddle for instance) & as their swimming ability improves they become more horizontal, which moves the swimfin out of the water when they do not need as much support. Because this swim float is worn on the back, it leaves children's arms completely free to move & is perfect for all swim strokes. Specifications Suitable for children approx 3-6 years (15-30kg)