Frame/Base: Black with Polished Aluminum finish. Back Support: Adjustable PostureFit SL for superior lumbar support. Tilt Mechanism: Tilt Limiter and Adjustable Seat Angle. Arms: Fully Adjustable (height, depth, pivot). Casters: Multi-Surface Casters with Quiet Roll (great on hardwood, tile, or carpet). The Herman Miller Aeron is engineered for maximum comfort, posture support, and durability. Whether for long workdays, gaming, or home office use, this chair adapts to your body to keep you pain-free and productive.