Blickman’s Double Post foot opertrated 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. The Benjamin Stand comes with 13 3/4 in. x 19 3/4 in. tray and its height adjusts between 39.5” and 62”.