[Attention Compatibility! ! !] Our headrest is fixed to the chair back with a 2-inch (5cm) wide clip. Please make sure that the thickness of your office chair back is no more than 2 inches before purchasing, or your chair has a place to fix the clip. The back thickness of most office chairs on the market is no more than 2 inches. [Installation Attention] 1. First tighten the clip to fix the pillow to the chair, tighten it by hand. If it is not tight, you can try to tighten it with a pliers tool. 2. Adjust the angle of the pillow to the position you need, tighten the hinge by hand, and then use an Hex wrench we provide to tighten the screws. No drilling is required for installation. [Adjustable Chair Back Headrest] This is a newly designed headrest that fits most office chairs, making your chair more comfortable. The padded headrest is height and angle adjustable and ergonomically designed to provide support for your head and neck. Much more cost effective than buying a new chair with headrest. [High Quality Material] This chair back sleeping pillow is made of elastic sponge plush cloth cover, and the head pillow is filled with soft sponge, which is comfortable and practical, soft and breathable, not easy to tear, and for long-term use. [Wide Scope of Application] This office chair headrest is suitable for most types and materials of chairs, computer chairs, office chairs, wooden chairs or plastic chairs. It can be easily installed and helps relieve your work fatigue and relieve neck pain, but it is not suitable for chairs with curved backrests, please make sure the chair back is flat before purchasing. Color:Black Material:Sponge Package Contents: 1 * Memory Foam Headrest(There are differences in printed words) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.