SITFIT® - Active sitting from SISSEL®. The perfect way to exercise your back with actively moving. Exercising pelvic floor, abdominal, back and stabilizers muscles, strong enough to stand on to improve flexabity in the ankle and foot, an active dynamic seating aid, Unit proven useful in cases of Dyspraxia and ADHD , relieves upper body tension and builds back musculature, comes with exercise poster, Phthalate and latex free. The valve permits pressure variation, comes in 33 cm and 36 cm diameter, can help prevent back problems by correcting poor posture. Cover available in blue, grey or burgundy for both sizes. See image for choice of colours.