The 100 V DC coil means it pulls in on a standard DC control supply; the IP20 finger-safe enclosure (VDE 0106) suits it for enclosed panel mounting where operators reach inside.
The AC-3 rating of 12 A at 440 V is the motor-switching current — it covers starting and plugging duty for three-phase induction motors up to roughly 5.5 kW at 400 V. AC-4 rating (inching/plugging) will be lower, so if your application involves frequent reversing under load, check the AC-4 curve. The 100 V DC coil is a specific control voltage — not 24 V or 110 V AC — so verify your control transformer or power supply delivers 100 V DC nominal. The contactor's 57 mm depth and 90 mm width fit a standard DIN-rail footprint, but the preassembled busbar adds a little length; plan for that in the enclosure layout.
Where it goes and what it connects to
The preassembled reversing busbar links the two contactor halves internally, so you only need to bring motor leads to the output terminals and line power to the input side. The 100 V DC coil connects to a control relay or PLC output — verify the coil's inrush current against your output card's rating. The IP20 enclosure means no live parts are exposed during normal operation, but the panel door should still be interlocked for safety.