Material:Eva foam. Dimension: 10.8 x 6 x 6 inch / 27.5 x 15 x15 cm.Weight:4.5oz.Recommended for ages 14 and up. Lightweight, but will present great resistance for your exercise in the water. Suspends you vertically in water to create a unique exercise experience. Work your upper body as well as your lower back and ABS for a total fitness workout. Water-based training burns calories—the greater the resistance in the water, the higher calorie burn you’ll experience.