The Siemens 3RT1016-1AL02 is a SIRIUS power contactor in the S00 frame size, rated for 10 A at 24 VDC and capable of switching motor loads up to 4.5 kW at 500 V and 5.5 kW at 690 V.
The 10 A rating at 24 VDC covers the coil circuit for most PLC or relay outputs — that's the current the contactor's own coil draws, not the main contact rating. The main contacts are rated by motor power: 4.5 kW at 500 V and 5.5 kW at 690 V, which tells you the inductive load it can handle in AC-3 duty (standard motor starting). Mechanical life is 30 million cycles, so this contactor will outlast most machines it's installed in.
Width is 45 mm, height 57.5 mm, depth 72 mm — that's a compact footprint for the S00 frame. Side-by-side mounting is allowed with a 6 mm gap to the side, which keeps the rail density high.