Large alloy base for stability twin wheel hooded castors heavy duty gas seat height adjustment posture curved seat with waterfall front sculptured posture curved seat with waterfall front stylish mesh backrest adjustable lumbar support synchronised mechanism with tension control height adjustable arm restsmeasurementswidth ndash 530mmdepth ndash 500mmback width ndash 530mmback height ndash 650 850mmseat height ndash 460 540mm