UL listed, The SJTW cable is 100% copper conductor inside, covered with heat-resistant PVC sheath and coated with flame retardant coating. Excellent abrasion resistance, oil and moisture resistance and flexibility. 3 prong 20 amp T-Blade Style straight blade, Male end (Plug): NEMA 5-20P, Female End: NEMA 5-20R, 125/250 volts.The plugs are wtist locking design with the L14-30 lock structure. Avoiding falling off due to weather conditions or man-made accidents.