[Adjustable Headrest] Ergonomically designed, provides support and comfort while reducing pressure on the neck and shoulder with the contoured-shaped/adjustable headrest, and promotes healthy posture. Milemont office chair believe so strongly that our often imitated but never duplicated headrest is the premiere neck/head pillow. [Lumbar Support] The lumbar support of our ergonomic mesh chair introduces a sneaky simple way to promote good posture while simultaneously relieving back pain while sitting. While keeping your spine in alignment our revolutionary lumbar support gently immerses your back into a Milemont quality experience unlike any other.... Our lumbar support system is designed to help relieve pain while sitting however it may not work for all conditions or completely eliminate all pain symptoms. [3D Armrests] Skin-friendly shape and surface - Blood vessels on your arms get much less compression, and the blood circulation is improving. Necessary support - Distributes weight evenly, avoiding unnecessary strain on the lower back, shoulders and spine. Spine alignment - Allows you to sit upright naturally and feel revitalized after being tied to your computer or desk all day. [Breathable Mesh] The durable mesh of the seat and back is designed to withstand weight up to 300 lbs. It won't deform for up to 2 years. Mesh cover provides great air circulation and allows you to sit without feeling hot or sweaty. It also features easy maintenance - Just wash the mesh in warm water on a gentle cycle with a cold-water rinse. [Tilt/Lock Functions] The only lever underneath the chair allows the seat to go up and down for 3.94''. What really matters is, by pushing the lever inwards/outwards from the middle of the chair, it locks/unlocks the tilting of the back. The chair FEELS AMAZING by tilting and locking the backrest to any place you want, and 90-117 degree is great and comfy enough for you to work or rest in Milemont home office chair for long hours.??Overall Dimension: 25.98"x 28.1"x 47.6"