Abstract: A device is disclosed for securing items, such as boat batteries and gas tanks, against theft and breakage. The locking unit is formed of dual base units, hingeably connected to vertical walls. The base units are connected to a support structure through use of screws or bolts. The top plates are connected to the vertical walls through use of hinges. The top plates can be provided with an adjustable locking member to secure various sized containers. L-shaped plates can be used to prevent any end to end horizontal movement of the container while the locking unit prevents side to side and vertical movement. The base unit can be one or two pieces, depending upon required adjustability. Parallel, opposing, side units, are affixed to the base unit at approximately right angles and a pair of top locking plates are then secured at right angles to the opposite end of the side units. The object is secured within the locking device through use of a lock which secures the top locking plates to one another.