Aeron is a swivel office chair with 5-Spoke base with castors.‎ Benefits • Three sizes to fit anyone in the first to 99th percentile • Composed of over 50% recycled material and now with ocean-bound plastic, Aeron is even more sustainable • Continual ergonomic enhancements like PostureFit SL®, 8Z Pellicle® and Harmonic™ 2 Tilt enable the sitter to maintain optimal seating posture and performance • Combined comfort, courtesy of enhancements that work together to support the human form • Accommodates a wide range of activities and postures you adopt while working Key Features 1.‎ 8Z Pellicle 8Z Pellicle offers unprecedented comfort through eight varied zones of tension in the seat and  back.‎‎ 2.‎ PostureFit SL The PostureFit SL supports the sacral region to nurture the natural S-shape of the spine, supports the pelvis, and activates healthful posture.‎‎ A secondary pad supports to the lumbar region.‎‎ 3.‎ Harmonic™ 2 Tilt The tilt moves with you naturally, allowing you to shift from forward to reclining postures intuitively and smoothly, and always at an optimal balance point.‎ 4.‎ Three Sizes Aeron comes in three sizes to ensure a better fit.‎‎ Arm Options No Arms Fixed Arms Height-Adjustable Arms Fully Adjustable Arms Fully Adjustable Arms plus Armpad Depth