miniature key
The English equivalent is a miniature switch or a miniature fuse (Miniature Circuit Breaker) and is displayed as an abbreviation with the word MCB. In fact, it is an automatic electromechanical switch that protects the consumer against short circuit and overload current. The miniature switch works automatically, so it will return to the circuit after being disconnected. Always keep in mind that miniature keys are non-adjustable and operate both magnetically and thermally.