Newbie with questions about zoomed ps20 powersweep

[CraigMac]

Got my tank used and it came with boxes of supplies. One item in there is a zoo med ps-20 power head. I'm not familiar with it so here are my questions:

1 what is it used for?
2. Can I use it as an air pump to make a bubble curtain?
3. How do you set it up and how do I know if the parts are all here?

Thanks for your help!