Fits Classic Aeron (no remastered) size A, B, C ('04 - '15) depending on what type of cylinder you have as later models they replaced with the claw top vs the pin top. This will work with pin top cylinders only. Will not work with remastered chairs. Comes with the knob and what you see if the pic. Email is with questions. It is part number 36 and 34 in the last pic of the parts diagram.
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