Abstract: A pushbutton resettable circuit breaker is shown having features to prevent manual opening by simply pulling outwardly on the pushbutton. In one embodiment, the pushbutton (16) is formed with slots (16b) which are configured to provide a reaction surface essentially inaccessible without a special purpose contact opening tool (30). The tool is provided with portions that are insertable into the slots and into engagement with the reaction surfaces for pulling the pushbutton out and manually opening the contacts. In a second embodiment, a small aperture 16k is formed through the rating tab and top and wall of the button and in alignment with a movable plunger (28). A special purpose contact opening tool (32, 34) can be inserted through the aperture to apply a force to the plunger and mechanically trip the circuit breaker.