Aeron’s three sizes—A, B, and C—were precisely designed to welcome a wide range of body types. Most ergonomic chairs accommodate people in the fifth to 95th percentile, but Herman Miller believes an even broader range of individuals deserve a chair that fits them: everything from the backrest height, to the seat width, to the tilt mechanism, all the way down to the size of the base. There’s an Aeron suited to nearly everyone, from the first to the 99th percentile.