An ABB residual current circuit breaker, with overcurrent protection (RCBO). This 20A 300mA DS201M RCBO has a Type B characteristic (tripping curve) in accordance with BS EN 60898. The DS201M is a 1P+N in two-modules for the protection of the end user, against overload and short-circuit currents; protection against the effects of sinusoidal alternating earth fault currents, protection against indirect contacts and additional protection against direct contacts. Applications: residential, commercial and industrial.