Wylex 10A 30mA RCBO SP Type B designed to be used with Wylex NH Consumer Units. Great quality, which is synonymous with the Wylex brand. RCBO (Residual Current Breaker with Overload Protection) combines functions of a MCB and RCD in one unit. Used to protect the particular circuit and preferable to separate RCD and MCBs. RCBO's detect over currents due to both overloads and faults. Suitable for general domestic consumer use and commercial use.