Need Help Quick Questions PLEASSE

[cavaliersfan23]

ok need help what is this on my protein skimmer and does it hook up to anything besides my skimmer? im confused.
thanks in advance.

 

[scsinet]

The way you've got it filled with water it looks like a bubble counter, but if it came with your skimmer, it shouldn't be filled with water. It's basically a muffler to keep the noise coming from the intake hose down.