Keep your core active and engaged, and encourage movement, all while seated, when you sit on this Black and Chrome Active Sitting Rolling Balance Desk Chair. This adjustable height rolling stool features a purposely wobbly cushion that is specially designed to allow you to sit still if needed or to move, sway, and wobble to burn calories while in your seat. The simple ergononmic office backless chair helps you sit healthier, is much more professional and attractive looking than sitting on a medicine or exercise ball. Sitting at work, or in your home office, can become a fun little workout while you work. 25" x 15" x 18"