Patented ergonomic design, specifically designed to fit all sizes (A/B/C) of the Herman Miller Aeron chair. Our patented third generation of headrests designed for the Aeron chair with a focus based on ergonomic principles for the neck and head. ENrich was created to move with a free-flow motion that follows the movement of your body in the chair. ENrich adjusts to offer ergonomic support in the upright position. 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 – Classic Carbon – Color Code 3D01 – The 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. Headrest only; CHAIR NOT INCLUDED. ERGONOMIC DESIGN – Provides head and neck support to help maintain comfort and alignment during long sitting sessions. Designed for ergonomic performance. Free-Floating System – Tilt and height adjustments move freely. Forward and backward angles can be locked for a custom fit and lasting comfort.