GUARDIAN's Ultra SourceŽ portable generators are the most powerful portable generators on the market and offer the best value in the business. Our 15,000-watt and 17,500-watt models feature our own OHVIŽ 992cc industrial grade engine. This powerhouse is renowned for its reliability, long life, impressive power and smooth, quiet operation. The 17,500-watt model comes standard with our 60 Amp manual transfer switch, making it easy to use during an outage. With up to 16 pre-wired circuits, all that's required is to start the generator and plug it in. By flipping a switch, the utility is locked out and the load is transferred to the generator.