Neutrik - True1 Power Connectors: 

The powerCON TRUE1 is a locking 20 A true mains connector. It replaces appliance couplers wherever a very rugged solution in combination with a locking device is needed in order to guarantee a safe power connection. The powerCON TRUE1 is a connector with breaking capacity (CBC), i.e. it can be connected or disconnected under load or live. 

Learn more here: https://www.onlinecomponents.com/featured/neutrik-34/neutrik-powercon-true1-cable-connectors?id=142