HW groups' PowerEgg2 is a "pass-through mains outlet" with two IEC-320 connectors – a male socket at the input, and a female socket at the output.
The device combines two functions. It detects the presence of mains voltage at the input (detector) and controls the voltage at the output (controller).
The detector reports the presence of an input voltage at an isolated relay contact. The output can be controlled either by an isolated contact or by an external voltage.
PowerEgg2 can work with any HW group device that has digital inputs and outputs, such as Poseidon, Damocles and I/O controller.