Western Railroad Discussion > How does a Mark 390 draft gear work?

From what I understand, the es44/et44's us an type f coupler with a Mark 390 draft gear.

Most draft gears I've seen have a post coming out of the front that the coupler sort of "runs" into, and compresses the draft gear, but the Mark 390 doesn't have that?

I'm curious which part is able to compress, as it looks like to me, that the Mark 390 must sit against something in the draft sleeve (on that part that kind of sticks out the sides/that is wider than the casing) that compresses the draft gear?

Apologies for no photos... I tried to upload some jpgs, but I kept getting an error.

https://www.wabteccorp.com/freight-car/end-of-car-systems/draft-gears/mark-390
I know nothing but this.
RB

It's a big piece of rubber in a sliding block..barely compressible but just enough to cushion. No springs or anything else....