This is an ABB RCBO breaker, model 2CSR254101R1504, designed to provide protection to up to four poles of a system. It has a rated current (Inom) rating of 50A, a rated residual current (Ires) rating of 30mA, a voltage rating of 400VAC, a form factor of DIN, and an IP20 rating. It is designed to provide over-current, short-circuit, and earth-leakage protection in both commercial and industrial electrical installations.