Abstract: A pair of vertical telescoping members are progressively lockable into any relative position to vary the overall length thereof by special locking hardware mounted on the inner member where it is not visible. The hardware includes a locking member movable in part by inertial forces between a released or unlocking position and a locking position where it forms a one way slip clutch with the inner surface of the outer member which permits the inner member to be raised which then preferably shifts the locking member into a release position. The inner member is moved further up or down to its desired position. Whenever the inner member is released, it is preferred that gravity will cause the inner member to move suddenly downwardly a small distance quickly to cause the locking portion of this member to move to its locking position.