The Siemens 3RT1066-6LA06 is a SIRIUS-branded power contactor in the S10 frame size, built for switching heavy motor loads in industrial panels. It accepts stranded cable from 70 up to 240 mm² on the power circuit, so you're looking at a contactor sized for big feeders — think main motor starters or large compressor duty where you need the full cross-section to keep voltage drop low.
Mounting is screw-fixed through a single 11 mm hole, with the vertical surface rotatable ±90° and tiltable ±22.5° front-to-back. Keep 10 mm clearance above, below, and at the sides, and 20 mm forward for arc-chamber venting. The solid-wire auxiliary terminals accept 2x 0.5–1.5 mm² or 2x 0.75–2.5 mm², max 2x 4 mm² — use ferrules on stranded for a reliable connection.