"Breather Filter" What is it?

[Goose55]

I've cued this Youtube to the part where Cummins Roger Hapka mentions "the breather filter" needing service at 75,000 miles. I am wondering. Is he speaking of the air filter? What is "the breather filter?"

Here's how the Cummins Diesel in the 2019 Ram HD Makes a Huge 1,000 Lb-Ft of Torque!

( http://www.TFLtruck.com ) Cummins Diesel in the 2019 Ram Heavy Duty Makes Astounding 1,000 Lb-Ft of Torque: Here is How!( http://www.patreon.com/tflcar ) ...

youtu.be

 

[18CrewDually]

The crankcase ventilation filter is under the rocker box top lid. Easy to change with typical 8 mm socket hand tools.
Plenty of youtube videos on it.