Apollo High Back Chair with Ratchet Back combines value, comfort, adjustability and quality to give you a comfortable seating option with a breathable, mesh back. Tilt tension control with tilt lock allows you to adjust the recline rate based on your weight. Synchro-tilt allows the back to recline in a preset ratio to the seat. Seat-height adjustment allows you to set the height to the desired position relative to the floor. Waterfall seat slopes to reduce pressure on the back of your knees for extra comfort through prolonged periods. Arms are both width-adjustable and height-adjustable for proper ergonomic positioning. 2.8" ratchet-back, height adjustment allows the backrest to easily adjust up or down relative to the seat for personalized lumbar region support and comfort. Chair is Greenguard certified to have low chemical emissions.