Care for your back… no extra time needed. … Activate more musculature … Gently mobilize your back … without extra effort. Comfortable sitting with balance effect Ergonomically shaped adjustable air cushion Strengthens back muscles and can help reduce back problems. Promotes upright posture. Optimized weight distribution on the thighs helps the veins. Ideal combination of ball cushion and wedge cushion in one product. Exercise poster and pump included. Size: about 40 cm diam. Colours: terra, black, blue, dark-red, dark-blue