Elevator adjustment and elevation adjustment, meet your different needs. No punching installation, save time and effort. Durable and comfortable, protect your neck and waist, perfect for office. It can only be used with a mesh chair. The top of the backrest of the mesh chair is bent and cannot be used. Suit for the person who sitting in office long time. Product Selling Point: 1. Breathable mesh surface, the product can be lifted up and down, head pillow can be turned. 2. According to the thick bottom of the measuring chair, you can choose the corresponding installation size.choose 2.2cm from 1.0cm to 2.0cm,choose 2.6cm from 2.0cm to 2.4cm,choose 3.0cm from 2.4cm to 2.8cm 3. This product can relieve the pressure of cervical vertebra. Due to manual measurement, there may be some error, please understand. 4. If there is sponge on the back, press and measure the thickness of the back. If the backrest sponge is too thick, it can't be installed with a retaining clip. 5. If the backrest sponge is too thick, it cannot be installed with a fixing clip. Product Specification: Product NameAdjustable Height Upholstered Headrest Materials:Nylon+Plastic Size: choose 2.2cm from 1.0cm to 2.0cm choose 2.6cm from 2.0cm to 2.4cm choose 3.0cm from 2.4cm to 2.8cm Color:black,gray,blue,green Package include: 1pc headrest 1set Long and short screw fittings Note: 1. Please Allow 1-2cm Differences Due To Manual Measurement. 2. Due To The Light And Screen Difference,The Item Is Color May Be Slightly Different From The Pictures.