NEW GENUINE Herman Miller Aeron Chair Lumbar Support Pad in Graphite / Black. BRAND NEW OEM Genuine Replacement Herman Miller Aeron Task Chair Lumbar Support Pad – Graphite – SELECT FROM SMALL SIZE A, MEDIUM SIZE B or LARGE SIZE C WE ONLY SELL GENUINE HERMAN MILLER PARTS – LUMBAR PAD ONLY – NO CHAIR. For Support and Questions. Aeron Fit / Size Chart. Use & Care Manual. Video Adjustment Information View these QuickTime videos to learn about the ergonomic adjustment options available on Aeron seating. Instructions shown are for all possible adjustments; specific adjustments vary according to chair model. (436KB) Seat Height Video. (390KB) Tilt Tension Video. (1.1MB) Arm Height Video. (718KB) Forward Tilt Video. Lumbar Pad Size A has 14 ridges – 19 inches wide Lumbar Pad Size B has 17 ridges – 20.25 inches wide Lumbar Pad Size C has 19 ridges – 21.5 inches wide. How can I determine my chair size if the label is gone? – To determine the size of your chair, feel underneath the top back lip of the chair’s backrest for a number of bumps. 1 bump is A, 2 bumps are B, and 3 bumps are C. One can also measure the seat pan width: Small A is 19 inches wide, Medium B is 20.25 inches wide and Large C is 21.5 inches wide. We accept most major credit cards in our showroom. The Original AERON® Chair. Herman Miller Mirra® Chair. Herman Miller Embody® Chair. Herman Miller Sayl Chair®. Herman Miller Setu Chair®.