This computer desk chair can lock its seat's tilt into one of several positions, and the tension of said tilt is precisely controlled by the knob on the underside of the seat. It also lets you adjust nearly every other aspect of its layout for specific ergonomic control, from the backrest to the lumbar support to the height of the armrests. This product is available in a range of colors, Graphite shown, and has a weight maximum of 300 pounds.