It features some simple new benefits that make this SitSmart even easier to use. SitSmart Posture Core positions your body to naturally relieve back pain and keep you sitting comfortably for hours. Measures 15.5” x 13”. Natural, safe and effective back pain relief Maximum comfort for longer periods of sitting 2x comfort cushioning & wider seating surface Works in any seat—office, car, home—or anywhere you sit! Tilts the pelvis upright to engage core muscles Weatherproof / waterproof Fits adults up to 300 lbs.