The Siemens 3RA1215-1AA15-1BB4 is a reversing combination starter in the SIRIUS S00 frame, rated for 1.1-1.6 A with a 110 VDC control voltage. It integrates a motor starter protector (MSP) with a reversing contactor pair into a single DIN-rail or panel-mount unit, so it handles forward/reverse motor control in a compact footprint — typical for conveyor drives, hoists, or gate actuators where reversing is needed. The 110 VDC coil means it's designed for DC control circuits common in battery-backed or industrial DC control systems; verify your control supply matches before wiring.
The 1.1-1.6 A range sets the motor full-load current window this starter protects and switches. At the low end it covers a 0.37 kW motor at 400 V three-phase; at the high end roughly 0.75 kW. The S00 frame size keeps the overall width to 45 mm, so it fits standard 45 mm-wide DIN-rail slots without crowding adjacent devices. The auxiliary contact configuration — one SPDT NO/NC on the MSP plus one NO on the contactor — gives you feedback for status indication or interlocking without adding a separate auxiliary block. That SPDT on the MSP can signal a trip condition back to the PLC.