The 3RT1054-1AS36: Power wiring accepts stranded conductors from 16 up to 70 mm², which covers the heavy feeds for a contactor this size. The screw-type coil terminals take 2x 0.5–1.5 mm² solid or 2x 0.75–2.5 mm² stranded, with a maximum of 2x 0.75–4 mm². That's enough for a long coil run without a separate terminal block. Footprint is 170 mm deep, 120 mm wide, 172 mm tall — standard for the S6 frame. Mounting is screw-fix with a vertical surface, rotatable ±90° and tiltable ±22.5° front-to-back, so panel layout has some flexibility.
Auxiliary switch is built in. Its rated breaking capacity at 24 VDC is 10 A — that's the contact rating for the aux circuit, not the main poles. At 48 VDC it drops to 2 A, and at 125 VDC it's 0.9 A. If you're switching a DC control load, size the aux contacts accordingly. Mechanical life is typical 10,000,000 operations — that's the mechanical endurance, not the electrical. Electrical life depends on the load category: at AC-3 (motor switching) you get 1,000 cycles per hour maximum, at AC-4 (inching/jogging) it's 130 cycles per hour. For high-duty-cycle applications, AC-4 is the limiting factor. That's fast enough for most motor starting and disconnecting applications.