The new Classica aquarium (RCD) circuit breaker is the first plug-in circuit breaker specifically designed for use with an aquarium. Traditional circuit breakers have been recognised as an important additional safety device by a number of aquarists as they provide additional protection from electric shock from faulty electrical equipment - particularly equipment that is submerged. However, traditional designs have one disadvantage, if the power to the breaker is disconnected the unit will trip, needing to be reset when power is returned. This can mean that after a power cut, important support systems are left unpowered until someone resets the circuit breaker! The Classica Circuit Breaker does not trip when the power is disconnected, ensuring that when power is restored, attached systems (e.g. heating and filtration) function as before.