Boss Office Products Black Contemporary Ergonomic Adjustable Height Swivel Task ChairHigh back styling upholstered with commercial grade fabric Sculptured waterfall seat made from molded foam that contours to the shape of your body Ratchet back height adjustment allows perfect positioning of the back cushion for lumbar support Adjustable height armrests with soft polyurethane Width adjustable armrest allows the user to move the armrests to match shoulder breadth Large 27 nylon base for greater stability Hooded double wheel casters