What kind of sump pump has 2 pits,2 plugs and one set of upper pipes going out?

Question:Hello! does anyone know what kind of sump pump has 2 pits(holes with covers) 2 cords to plug in,yet only one has upper pipes that pump outside? the other hole has some black tubing in it and it does make a noise so it must have a function?

Answers:
Best guess on having two pits is that either there was a plan for another pump or they connect to hold more water. The two plugs are probably one for the pump and one for a seperate float that turns on the pump. Some pumps have built in floats while some use a seperate one. You only need one set of piping going out and if another pump would be installed in the other sump, the piping would just tie into the existing pipes.