Dimensions: 73 mm deep, 45 mm wide, 70 mm high.
Coil rated 72–125 VDC; pick-up at 70 % of rated value, drop-out typical at 0.7 of initial value. Holding current averages 7 mA; inrush peak is 1.1 A. DC operate time 25–45 ms, arcing time 10–15 ms — fast enough for interlocking and auxiliary contactor control. Contact ratings span the railway voltage range: 10 A at 24 VDC, 4.7 A at 60 VDC, 3 A at 110 VDC, 1.2 A at 220 VDC, and AC ratings up to 10 A at 230 VAC and 3 A at 400 VAC. The locked-rotor current peak is only 0.04 A — this is a control relay, not a motor starter.
No official successor is listed; the 3RH2131-2XF40-0LA2 remains the active railway DC-coil variant in the SIRIUS range.