This European Standard specifies safety requirements for construction, performance, sizing and marking for swimming aids intended to assist users with movement through the water in the early stages of water awareness, whilst learning to swim or whilst learning part of a swimming stroke. It also gives methods of test for verification of these requirements. This Part of this European Standard applies to class C devices that are designed to assist with improving specific elements of the stroke and which have either inherent buoyancy or can be inflated. It includes devices that are held in the hands, by the body or between the legs. It does not apply to buoyancy aids, lifejackets or aquatic toys.