What it is and what it does
The Siemens SENTRON 5TT5033-0 is an Insta contactor with four normally-closed (NC) contacts and no normally-open contacts — a dedicated NC-only switching block. It is rated for 25 A at 230 V AC (operational current) and can handle a maximum of 400 V AC. The coil actuation accepts both AC and DC (rated 230 V AC / 220 V DC), making it flexible for control circuits that may be either. The IP20 enclosure means it is intended for installation inside a panel or enclosure where it is protected from direct contact and large debris, but not from moisture or dust ingress.
Where it fits in the panel
The contactor occupies 2 modular width units (18 mm per unit, so 36 mm) on a DIN rail. Its dimensions are 90 mm high, 35 mm wide, and 71 mm deep, with an installation depth of 64 mm. The manufacturer explicitly notes that spacers must be provided for heat dissipation — this is not optional; the 2.2 W power loss per pole at rated current needs airflow between adjacent devices. In a crowded DIN rail, skip a slot or use a vented separator.