Pneumatic Stool w o Back Aluminum Base Doppler Transducers wheel frame) 38 1 2 (980 Select Ear:Left Ear wheel frame) 38 1 2 (980 mm) Height of chassis 6 (150 mm) * Hand operated air spring pneumatic height adjustment load capacity under normal use 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