Abstract: A device (10), such as a ladder, scaffold, piece of furniture or a support for any other appliance has at least two legs (12;14), each of which has a slidable leg part (30;32) slidably positioned with respect to another part (18;20) of the device to form a leg having an adjustable length. A locking structure (34;36) is arranged to prevent movement of each of the slidable leg parts (30;32) with respect to said other part (18;20) of the device in a locked state of the locking structure (34;36), and to allow movement of each of the slidable leg parts (30;32) with respect to said other part (18;20) of the device in an unlocked state of the locking structure (34;36). A flexible member (38) interconnects the slidable leg parts (30;32) and is arranged such that it pulls the locking structure (34;36) into the unlocked position when strained under the action of gravity acting on at least one of the slidable leg parts (30;32).