Lorell Ergonomic Chair, w/ Arms, 27-1/4"x25-1/2"x41-1/2", Black High-performance ergonomic chair with contoured seat and back includes built-in lumbar support for optimum support. Functions include pneumatic seat-height adjustment, 360-degree swivel, and 2 to 1 synchro tilt control with adjustable tension and tilt lock. Mid-back chair also offers padded adjustable arms and heavy-duty nylon base with dual wheel carpet caster.