Reliance Controls 30-Amp (4-Prong 1-Circuit) Outdoor Transfer Switch - CSR302 Outdoor, NEMA 3R transfer switch Easy to install, easy to use Maximum generator running watts: 7,500 Product dimensions: 6.25L x 7.5W x 8.75H Ideal for single-circuit control of farm buildings, irrigation systems, community wells, traffic signals electric heat and more