This is a Refurbished Herman Miller Aeron in size C, which includes standard back adjustable lumbar support.  The Aeron line is best designed for lumbar support and breathability while seated due to it's mesh fabric and ergonomic design.  Designed for a wide range of body types, it's truly been a pioneer in the office furniture industry. 
 
Features:
Breathable suspension keeps you cool and comfortable
Adjustable PostureFit SL pads provide lumbar support and stabilize the base of the spine
Harmonic Tilt provides a smooth and balanced recline
Fully adjustable arms (height, depth, and angle) allow for a custom fit
Composed of recycled materials
 
Overall Dimensions:
28.3"W x 28.3"D x 40"-45.4"H