My sister-in-law sent us a picture of this. It is in a closet in her finished basement and she isn't sure what it is or what it's connected to, but it is dripping. As a layperson, my only guesses are that it has something to do either with either a condensate line and/or plumping waste water up to the sewer line which I assume is above their basement level. Any help identifying it would be appreciated.
It appears to be a Plastic Water Softener Air Gap...what ever that is!