What kind of sankey tapper you using on your american kegs??

I see these D style tappers but can't figure out the flow of things on them. Is the gas coming in the top and the beer going out the side?
I'm trying to figure out what fittings I might need. All I'm running is these ball locks on the corny kegs, so I'll need some new fittings.

Local beer store is selling Sammy Oktoberfest in 5 gal kegs. I gotta get me one.