These miniature circuit breakers are UL489 listed for use as branch circuit protection or as supplementary electrical protection. Also known as branch circuit overcurrent devices, they open the circuit upon overload or in the event of a short circuit to protect equipment from damage. Mount these circuit breakers on standard 35mm DIN rail in control panels, motor control centers, panelboards, and other low-voltage electrical applications. One-pole breakers protect a single circuit, 2-pole breakers protect two, and 3-pole breakers protect three.