The Siemens 3RT2018-4AK62 is a SIRIUS power contactor in the size S00 frame — the smallest footprint in the SIRIUS family, at 45 mm wide, 73 mm deep, and 58 mm tall. The coil pulls 0.24 A at both 50 Hz and 60 Hz, rated at 110 V for 50 Hz and 120 V for 60 Hz. The auxiliary switch is included, terminated with ring cable lug connections on the magnet coil — a detail the wireman will appreciate for a clean, torque-able termination.
This contactor is rated for different switching frequencies depending on the load type: 1,000 operations per hour at AC-1, 750/h at AC-2 and AC-3, and 250/h at AC-4. The AC-3e rating also sits at 750/h. The arcing time runs 10 to 15 ms, with a make time of 4 to 15 ms at AC. The auxiliary contact carries 10 A at 24 V, 14 A at 480 V, and 3 A at 400 V — so it handles pilot-duty and control-circuit loads across a wide voltage range. For motor loads at 230 V it's rated 2 hp, and at 400 V it switches 3 A in the auxiliary circuit.
At 45 mm wide on the DIN rail, this contactor takes up one standard 45 mm module — same as a typical miniature circuit breaker. The ring cable lug connection on the coil means you'll want a ring terminal crimped to the control wire, not a bare stranded end. The screw fastening method gives a solid mechanical hold; the snap-on feature lets you clip it onto the rail without tools for initial placement. That's tight enough for a packed enclosure but leaves room for airflow if you're running near the 60 °C ambient ceiling.