INFLATABLE DONUT CUSHION: When fully inflated the outer diameter of this donut cushion measures 38cm (15 inches) with an inner diameter of 10cm (4 inches). The height of the cushion is 9cm (3.54 inches). The outer material is made out of long lasting velvet and can support up to 100kg (220lbs). When sat on the cushion will distribute your weight without putting pressure on your perineum, lower back and hips. This ergonomic cushion will support healthy blood circulation and promotes good posture. PORTABLE AND CONVENIENT: This cushion is lightweight and can be easily inflated and deflated. Included is a small pump which measures 17cm (6.69 inches) in overall height as well as a portable holiday travel pouch which measures 18 x 18cm (7.09 x 7.09 inches). The cushion can also be inflated by using your mouth. When the donut cushion is not in use simply deflate it by squeezing the open valve and then fold it up to store in the travel storage pouch to keep it clean and free from damage. ADJUSTABLE TO YOUR NEEDS: Since this cushion is inflatable you can choose how soft or firm you want it. For a firmer seat, add more air into the cushion using the pump. If you require less pressure, deflate the cushion to suit. The cushion will fit to the shape of your bottom and is non-slip making it safe for use with most chairs. Sit comfortably once again and take pressure off the areas causing you pain and discomfort. CAN BE USED ALMOST ANYWHERE: You can now feel comfortable wherever you may be sitting, be that at home, at the dining table, on the sofa or in the office. Suitable to be used when travelling in a car, train or airplane. Can be used for relief from painful conditions involving coccyx, sciatica nerve, piles/haemorrhoids, pregnancy, tailbone, prostate and bed sores. Also can be used with wheelchairs and when sitting up in bed.