The Siemens 5SU1654-1KV13 is a combined residual current device and miniature circuit breaker (RCBO) in a single 1+N-pole module. It integrates Type AC residual current protection at 300 mA with a C-curve overcurrent trip at 13 A, all within a 70 mm wide housing.
The 300 mA residual sensitivity is Type AC, meaning it detects sinusoidal AC earth faults only; for pulsating DC or mixed-frequency fault currents, a Type A device would be required. The 70 mm width (4 modules on a DIN rail) fits standard Siemens distribution boards and leaves room for adjacent devices in a crowded enclosure.