I noticed the new securityProbe 5E has a jumper in the back, what is this used for?

AKCPsecurityProbe Series, Support

That jumper is a 120 ohm switch, as in some cases of Modbus integration 120 ohms is needed on the RS485 input, so that has been added.

AKCPI noticed the new securityProbe 5E has a jumper in the back, what is this used for?