Industrial plug and socket specifications for a common, according to IEC60309 standard (International Electrotechnical Commission standard) and Chinese (GB standard) by current points, divided 16A, 32A, 63A, 125A. 2, according to the American standard current UI specifications for 20A, 30A, 60A, 100A. 3, a variety of compatibility between IEC and GB standard products compatible with U.S. standard UL 16A 20A industrial plugs and sockets 32A IEC and GB standard products compatible with U.S. standard UL 30A industrial plugs and sockets 63A IEC and GB standard products compatible with U.S. UL standard industrial plugs and sockets 60A IEC and GB standard products compatible with U.S. standard UL 125A 100A Products industry standard plug socket voltage difference between one color and the blue represents the voltage is 230V products. 2, the red represents the voltage is 400V products. 3, whole body white products represented 50V ultra low voltage products. 4, purple label products represented and significance of ultra-low voltage 20V Product number of poles 1,3 P (2P + E) or Single Phase English said 3Pole said Firewire + neutral + ground 2,4 P (3P + E) English, said 4Pole or 3Phase, said three FireWire + ground 3,5 P (3P + N + E) English, said 5Pole or 3Phase, said three FireWire + wire + ground zero absolute price concessions