Ergohuman Mid-Back Mesh Chair: The Ergo chair feature; Pneumatic height adjustment, tilt tnesion control, adjustable lumbar support, multi-dimensional armrests, back angle adjustment, synchro tilt mechanism, 3 postion tilt lock, back height adjustment and seat depth adjustment. Overall size: 26"W x 27.5"D x 46-51"H. Seat: 19.5"W x 15.5-17.75"D. Back: 21.25"W x 27.5"-29.5"H. Usually ships within 24-72 hours! Assembly required.