Please be sure to select the correct’Size’. H3 – For individuals under 5’11” (Under 180cm) H4 – For individuals 5’11” or taller (Over 180cm) COLOR AND WEAVING – The Engineered Now Headrest perfectly matches your Aeron Chair in comfort, quality, color of frame and Mesh and the mesh weaving. Please make sure you choose the right Model and color of your chair, see our images and text for assistance. EXPERIENCE THE ULTIMATE UPGRADE TO YOUR HERMAN MILLER AERON – The H4 ENgage is our full size headrest designed to provide you with the neck support the Aeron Chairs are missing. The H4 comfortably fits users over 5’11, offers more adjustability and a 20% larger pillow size. CARBON COLOR – Perfectly matches your Classic Aeron Chair in comfort, quality, and color, with complementary Carbon Mesh. [MATCHES CLASSIC AERON CHAIR MODELS YEAR 2016 OR OLDER] IMPROVE POSTURE AND PRODUCTIVITY – Our headrests are ergonomically designed to support the head and neck, helping you stay comfortable, aligned and focused throughout the day. ADJUST TO YOUR COMFORT- EN headrest are intended to be free flowing. The tilt and the vertical adjustments are free-moving, while the forward and backwards adjustments can be locked to your best comfort.