GenTran 25-Foot 10/4 Generator Contractor 4-Wire Twist Lock Extension Cord Set With Two NEMA 5-20 Duplex GFCI Receptacles And Two 20 Amp Breakers D10425DW (Discontinued by Manufacturer) GenTran contractor extension cord set is a safe, convenient way to power electric tools and appliances using a portable generator Ideal for jobsites when GFCIs are required to comply with OSHA Duplex receptacles are housed in an aluminum weatherproof junction box with spring-loaded cover Made with UL Listed components; 125-volt use (30-amp) Model D10425DW