BackJoy is an effective seating solution specially designed to help relieve and prevent back complaints. BackJoy creates an active sitting position and corrects the sitting position making sitting upright easy. SitSmart Core Traction has a premium fabric covering with anti-slip grip areas for all day comfort and stability along with extra cushioning. SitSmart Core Traction positions your body to naturally relieve back pain and keep you sitting comfortably for hours. Specifications Works in any seatoffice car homeor anywhere you sit! Adjust the sitting position to engage core muscles Max Weight capacity: 150kg Hip Size 95-120 cm How do I know what size to get Your size is determined by the size of your bottom and how much you weigh. The larger those measurements the larger the size you will require. When you refer to the size guide you will notice that there are ranges – your size is where your measurements fit into the ranges.