Jumbo model,double-post,instrument(mayo)stand,stainless-steel,20" W X 25" D tray.DOUBLE POST FOOT-OPERATED MAYO STANDS are number one in ease and convenience. Just lift the tray-frame - it automatically locks. To lower, hold the tray-frame and press the foot-operated control button. Release to lock in-place. A guard over the foot-button prevents accidental release.