dometic air con can anybody identify this model please

[Scout]

I've got a dometic air con unit on my motorhome roof, but I'm have a problem the the slider in pic number 2, it wont move, I'm looking to download a manual for it but I'm not sure what model number it is, does anybody know? and if anybody also knows how to operate the slider that would be great too. I've tried pushing but I didn't want to apply too much force and break something.

 

[M-J]

Freshjet?

Or maybe B1500S

Model is likely to be displayed on the front of the roof unit.

 

[Scout]

Freshjet?

Or maybe B1500S

Model is likely to be displayed on the front of the roof unit.

thanks I cant see a modle number on the front, there might be a small plate but its hard to see and im long past climbing up there, I google B1500S and see if it look like it.