The LX1FJ090 is a replacement contactor coil for the TeSys F range, rated for 90 V AC control circuits at 50/60 Hz. It pulls the contactor in; when the coil fails, the contactor drops out.
What the 90 V AC rating means for fit
The 90 V AC control voltage is specific: it is not the standard 110 V or 230 V coil found in most panels. If your control transformer or PLC output is feeding 90 V AC, this coil matches exactly. The 50/60 Hz rating means it works on either line frequency — no derating needed when swapping between 50 Hz and 60 Hz supplies.