Question about pumps and a protein skimmer

Hello,
My friend gave me a amiracle sump that came with a pump and protein skimmer that was in his father attic for a few years, I think the protein skimmer is missing parts. It has an round opening at the bottom and a square fitting half way up with a small hole and what apperars to be a drain fitting on the cup, it is fitted so it hangs perfect in the sump, how would I go about getting this thing to work?
The next question is it came with a utility 3 pump, does that mean 300 gallon? If so would that be enough flow on a 45 gallon with 4 feet of head. Just wondering because I have a mag 9 new in the box that I can return if the other pump will work.
Thanks

 

we will need pics to answer these questions of the possible missing parts. And I don't think the '3' means 300 gallon, it is probably just a model number. try to google the name of all the equipment and see what you find out.

 

I am having trouble getting the picture bigger. But there it is it has a 2inch opening on the bottom.

 

Yeah, if there is a crack water will leak out.
Spare others the trouble;D

 

Pan I think those smilies should be your signature cause you love to post them
On a serious note you are right