An ergonomic inflatable seat cushion which is designed to encourage a balanced pelvic position and good sitting posture, activate your core trunk muscles and support the spine whilst 'actively' sitting. A convenient, portable (there's a carrying handlle) alternative to using an exercise ball chair - simply place it on whichever chair you choose, wherever you are - and with similar benefits. Increasing or reducing the inflation adjusts the level of stability. Suitable for supported exercise, and remedial use for back pain and sciatica. Class I Medical Device compliant with European regulation. Material: High-quality PVC, free from latex, phthalates, BPA, lead Size: 36 x 36 x 7 cm