What is this connector on the breather hose?

[Fredrikkk]

Does it measure the oil level venting out? Or does it like.. cut fuel if too much oil comes through?

I've been wondering forever..

[R.O.R-2.0]

its a heater to keep the blow by gasses from freezing..

nothing complicated at all.. no oil sensor, or anything like that, just a simple little heater..