This Current Transformer (CT) sensor clamp is for use with existing Efergy E-Max transmitters only.
If you have two-phase power, you can buy a single-phase E-Max and one of these to get the number of sensors you require. Or, if you move to a home with three-phase power, buy two additional CT clamps.
It has an internal diameter of 16mm and can measure up to 120 Amps.