VIVA OFFICE High Back Ergonomic Nylon Base Office Chair with Adjustable Armrest, Black With High quality material, world class ergonomic design, affordable prices and great sitting experiences, we always committed to delivering the best and different office chairs to you and always ready to help you. Adjustable tilt tension, seat height and armrests. Synchronous tilt mechanism with tilt lock allow for movement or stability as needed. Sturdy seat cushion can accommodate person who weighs 250 pounds. Waterfall seat design eliminates leg fatigue. High quality Nylon base and Nylon casters. Easy assembly upon arrival. We also provide component-exchange in two years