Drains - trying to understand them - advice please?

Question

I now know what an interceptor cap looks like. What is the thing called that it screws onto and is chained to (the thing like a giant vacuum flask)?

Answer 1

Are you trying to install a bathroom drain or a faucet? It sounds like a bathroom but I'll venture a guess as the giant vacuum flask is probably the water pump (is it a large black, full of air kinda plastic bubble/bag thing?).