Genuine OEM Herman Miller Aeron Classic arm yoke assembly from the fully adjustable thumbwheel (“wheel style”) arm system. Compatible with Aeron Classic chairs in Sizes A, B, and C when matched to the correct side and configuration. Shows normal signs of previous use including light cosmetic wear from office use. Fully functional and ready for installation. Please review photos carefully to confirm compatibility with your chair before purchasing. Designed for Aeron Classic models and not the newer Aeron Remastered version. Restore the functionality of your Herman Miller Aeron Classic chair with this genuine OEM fully adjustable arm yoke assembly. This is the wheel-style (thumbwheel) version used on Aeron Classic chairs, allowing arm height adjustment through the rotating adjustment wheel. Herman Miller’s service documentation identifies this as the Aeron arm yoke assembly for Classic chairs. Genuine Herman Miller OEM part. Fits Aeron Classic chairs. Wheel-style (thumbwheel) adjustable arm system. Available for Size A, B, or C chairs. Ideal replacement for broken, worn, or damaged arm assemblies. Compatible with Aeron Classic models, not Aeron Remastered chairs. Thank you for supporting a teacher turned small business owner!