NEMA 5-15 Plug to IEC C13 Connectors provide a secure connection. The C13 connector is specifically an IEC 60320 C13 plug, or more commonly referred to as an IEC plug. Applications that benefit from these connectors include industrial processing, which may have higher than average vibration as well as medical appliances that require continuous operation. The lock engages when the plug is inserted into any universal IEC C14 inlet. You can simply disconnect it by depressing the red release buttons.