One-piece, American-made, Black, nylon base Full size diameter top and base for comfort and stability 5-leg design for greater stability Firm polyfoam padding 4" thick seat for extra comfort 2.5" dual wheel casters Single lever, pneumatic height adjustment All seats have 3/4" thick solid plywood base Premium, stain-resistant, woven, knit-backed, vinyl upholstery Knock-down design saves on shipping Easy, no tools required assembly Customizable with options including a backrest – see options 250 lbs. load capacity under normal use