The Siemens SIRIUS 3RH1140-2VB40 is a coupling relay — a 4-pole auxiliary contactor block sized S00, designed for switching auxiliary circuits in control panels. It carries 4 normally-open instantaneous contacts and is rated for a 24 V DC coil. That matters when you're passing PLC-level signals through the same block that handles a solenoid.
The contacts are rated for 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V. The 400 V rating at 3 A covers auxiliary switching in 400 VAC motor starter circuits.
The S00 size — 45 mm wide, 60 mm high, 73 mm deep — is the standard footprint for Siemens SIRIUS auxiliary contactors.