Frame Material Engineered Plastic. Maximum Weight Recommendation 350 Pounds. Item Weight 3.5 Pounds. Headrest, Hex tool, Replacement Bolt for A-Size Chairs, Spare Caps, Instructions. 12″D x 7″W x 8H. Engineered Now is proud to offer the fine-tuned H3 and H4 Headrest to enhance your Herman Miller Aeron, elevate your comfort and improve your productivity. From large corporations to home offices, these ergonomic add-ons are a must for every avid Aeron chair owner. Eliminate upper-back, shoulder, and neck pain by adding this headrest to your chair today! We offer the best prices around on high quality products. Our E-store includes media such as books, movies, music and games while offering electronics, toys, sporting apparel, clothing, tools, general home, garden items and more. We are always working hard to ensure your package arrives as soon as possible. We do not accept P. Please provide a physical address. We try our very best to make sure every customer is completely satisfied. If there’s a problem, message us! We’re happy to help.