Premium 23 die cast aluminum base with satin finish top * 5-leg design for greater stability * Full size diameter top and base for comfort and stability * 4 thick seat for extra comfort * Black hooded dual wheel nylon casters * Pneumatic height adjustment * All seats have 3/4 thick solid plywood base * Lever controls height * Knock-down design saves on shipping * Easy no-tools required assembly * Premium stain-resistant woven knit-backed vinyl upholstery * 250 lbs. load capacity under normal use