This is a left/right set of Remastered Aeron armrests with armpads. They are in decent used shape for the most part, except for the armpads themselves. Taken off a used 2018 Remastered Aeron recently. The armpads will need to be replaced soon. The internal foam of the armpads has shifted and collapsed from use; while the armpads LOOK fine from the outside, the inside is “lumpy” and the outside lacks the smooth feeling of new armpads. These are what Herman Miller calls “fully adjustable” armrests. Informally known as “4D” armrests. This means the armpads. To be perfectly clear, these Herman Miller “fully adjustable” or “4D” armrests are NOT a 1:1 copy of Steelcase’s 4D armrests; these Herman Miller armrests do NOT slide laterally but only rotate/pivot laterally. These can technically be fitted to a Classic Aeron — message if you need assistance. These armrest yokes will physically bolt up to the Classic Aeron’s swing arms… If you don’t understand what this means, then, this swap may be too advanced for you.