The Herman Miller Classic Aeron Chair Back Frame Size B Replacement is a high-quality, authentic replacement part specifically designed for the Herman Miller Classic Aeron office chair. This back frame includes a lumbar pad for added support and comfort, making it an essential component for maintaining proper posture and ergonomic alignment while sitting at a desk. The Herman Miller brand is known for its premium office furniture, and this chair back frame is a reliable and durable option for those looking to replace or upgrade their existing office chair. Note: The bolts to attach the back to the seat are not included. I’ve listed the condition as used however I don’t find any wear or any blemishes.