Any Keystone ZEPPELIN owners out there???

just bought a 2004Zeppelin 281 and was underneath it yesterday and midway on the trailer is some type of black cover that extends the width of the TT and hangs down about a foot (see pictures) and it has some type of hose or drain coming out of it. can anyone tell me what it is???


this is looking at it from the back of the tt.



this looking at it from the front.

thanks for any help.