Our training aids are designed to help you get the most from your swim workout. Each training aid works a particular part of your body, so you can focus on increasing strength, stamina or tone where it suits you. Featuring Biofuse Technology. Designed for the fitness swimmer who has established leg/ankle strength. Improves kick, ankle flexibility, leg and core strength. Creates max resistance in the water for speed development. Can also be used for active recovery. Tabs at the front and back of the foot hole, make it easier to fit and remove fins.