Reliable product from the technology leader. When it comes to ready availability, easy installation and fewer callbacks, you need a manufacturer you can trust. Our products and systems are engineered to take on the most demanding conditions, always service and maintenance network, complete support is always there. With a thermal-magnetic design, this Siemens 30/30 Quad Circuit Breaker is installed to provide overload and short-circuit protection for the electrical wiring in your house.