The iOO Chair is a sleek, powerful product of generations of development and refinement. All of its controls have been integrated into a single mechanism for quick adjustments that are effortlessly simple. Tilt tension control with tilt lock allows you to adjust the recline rate based on your weight. Back-angle adjustment sets the back angle for personalized comfort in a reclined position. 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. 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. The arms are both width-adjustable and height-adjustable for proper ergonomic positioning.