This office chair features an ergonomic design that's sure to give you plenty of support as you work. It has an engineered wood and steel frame with breathable mesh panels on the seat and back. The frame rests on five soft caster wheels for easy movement over a variety of floor types. The curved backrest adds support to help your posture. Plus, flip-up arms provide relief to your shoulders and neck while also catering to those who prefer an armless task chair design. It also includes a height-adjustable seat, a swivel function, and a center tilt mechanism to suit your needs. Features The diameter of the wheelbase is 10