Automatic leveler installation

I just picked up an automatic air bag leveler at the parts house that I'm going to install on a system that did not come with it to begin with ( and was not a factory installation so no factory parts) so I'm flying blind here. and I got the thing home and I'm drawing a blank., It's been years since I've serviced one of these things and I can't for the life of me remember the connections I know one exhausts, it looks like that is the center fitting but I cant tell which one needs to be supply and which one needs to go to the bags and if I need to remove one of the internal check valves on the bag one?
THe Control unit is a Prima brake componants Leveling valve LV90054007
THanks

 

Sure does. Thanks.