The Siemens 4EU2732-0FQ08-0EA0 is a 3-phase filter reactor rated 37 kVAR at 400 V, 50 Hz. It is designed for harmonic filtering or power-factor-correction duty in industrial low-voltage networks. Terminals are free conductor ends, so you land your own lugs or ferrules directly.
The 37 kVAR reactive-power rating compensates that amount of reactive energy at 400 V, 50 Hz. The 7 % impedance is typical for a detuned filter reactor, shifting the resonant frequency away from the 5th and 7th harmonics.