Need to replace this - but what is it?

[Tom Randall]

I am getting ready to start my fulltiming adventure and need to find out what this is.... Since I have only used my Airstream once, I never used this. If my memory serves me, I think the seller told me it was for - phone and cable - sound right? Where do I get this?

I checked with Airstream and they said it did not leave the factory with this on it....

This is a 1990 32' Excella 1000. Thanks!