NS80 Skimmer Users... Did I get the wrong pump?

[SonRK]

I know the included instructions stink, but I watched a few videos and everyone seems to attach the pump into the body's hole... except mine goes in and is not in tight at all.

It's just there loosely hanging out. There's no way this would work in my tank! Am I missing something out, or did I receive the wrong pump/body?

 

[hijinks7]

I have this skimmer for my QT and the pump goes in with a bit of resistance but you can pull it out easily. It sticks a bit but runs fine.