The Herman Miller Aeron Chair Replacement Seat Pan with Rare Brown Mesh “B” is a genuine OEM product designed to replace the seat pan of an Aeron office/desk chair. The brown mesh is a rare feature that adds a unique touch to the chair’s design. The product is manufactured by Herman Miller, a well-known brand in the office furniture industry. The replacement seat pan is compatible with the Aeron model and has not been modified. Size B with discontinued, impossible to find: BROWN MESH. This relic has been stuck in a warehouse for decades. Check out this condition! The pad located under where one’s knees would be while sitting is a little flaky. Contact me with any questions at anytime.