The aqua sphere ergo buoy is a swim training aid constructed to work the swimmers upper body and immobilise legs to create drag its ergonomic design fits comfortably between legs and helps isolate arm motion to improve stroke form while swimming the buoy is equipped with removable inserts for adjustable buoyancy and is made from durable eva foam that is ultra soft and will not saturate or waterlog this blue swim training tool has a belt with quick release buckle that keeps legs together and