These heavy duty three-pole, four-wire grounded generator extension cords feature fully molded NEMA L14-30 plugs and connectors. The widely used 4-prong twistlock ends are most commonly found on the majority of medium to large size portable generators and transfer switches. The abrasion resistant SJTW jacket is rated for hard service. It remains flexible in the extreme cold and is heat-resistant to 221°F. These cords are built with heavy strand 10AWG wire for limited voltage drop, making them ideal for contractors, mobile businesses, and home emergency power systems.