Abstract: A lock mechanism for cases or containers which includes engagable lock elements, one of which can be rotatable into a lockable and a non-lockable alignment. The exposed surfaces of the lock elements are flush with surrounding wall surfaces of the case or container when the mechanism is locked. The mechanism can be concealed by matching the exposed surfaces of the lock elements with the surrounding surfaces of the case or container. The mechanism include springs which bias the lock elements. Appropriate spring strengths can be selected to prevent infants and young children from opening the mechanism.