Brand New Herman Miller Aeron Replacement Seat Mesh Size B – Graphite Color. For sale is a brand new Herman Miller Aeron graphite replacement seat mesh for the classic size b chair. This item is new and does not include screws. As this is new, screw holes will need to be made to fit your specific model. We strongly recommend using clamps. During installation for ease and correct alignment. Once any holes are made in the mesh, the item becomes non-returnable. May appear smaller before installation. When correctly installed, the mesh stretches and creates the proper. Tension required for comfort and support.