Standard insulated, two conductor white cord with a rib on one conductor for polarity indication. 18 AWG SPT2: 500 foot Spool, 18 gauge copper. stringing: 41 strings/ 34 gauge. Insulation Thickness: 0.030. Insulation Material: PVC. Working Voltage: 300V AC. Temperature Range: 105 degrees C. Size: Nominal O.D.: 0.104 x 0.210 UL Listed and CSA Approved. Wire only. Plugs and sockets sold separately.