Made from Buoyancy foam NBR/PVC material. Light weight and extremely durable. Super soft cushion, fantastic comfortable feel. Non-slip surface and base prevents from sliding. Closed-cell foam does not absorb water, and is easy to clean. Stand on 1 or 2 legs and perform squats, lunges and reaching touches to improve strength and stability. Create for balance training, coordination and reaction training, posture stability training, balanced motion cardio training, improvement of coordination, reaction, flexibility… so on.