HOLLUDLE Ergonomic Office Chair with Foldable Backrest, Computer Desk Chair with Flip-up Armrests, Mesh Lumbar Support and Tilt Function Big and Tall Office Chair, Black[SPACE SAVING]In addition to foldable arms, this desk chair features a folding backrest function. When you don't need to sit down, the chair can be folded up to leave most space. How to fold the back: Step 1 is to press the buttons on both sides with your thumbs and Step 2 is to fold the backrest with other fingers [MESH LUMBAR SUPPORT]Equipped with a lumbar support design that is a double layer back, the computer chair provides very comfortable