A standard insulated, two conductor cord with a rib on one conductor for polarity indication. 18 AWG SPT-1 PARALLEL POWER CORD SPECIFICATIONS: AWG Gauge: 18 Gauge copper Stranding: 41 strands/ 34 Gauge Insulation Thickness: 0.030 Inch Insulation Material: PVC Working Voltage: 300V AC Temperature Range: 105oC Size: Nominal O.D.: 2.65 x 5.35mm or .104 Inch x .210 Inch UL Listed CSA Approved