This is an excellent positive head Monsoon single impeller shower pump, bought off ebay on the instruction of a plumber, who then said we should have a negative head one after he fitted it in and said there was not enough existing water pressure! So we bought a negative head pump, again off ebay, and he disappeared off the scene. A much better plumber diagnosed the issue as an airlock, and fixed the problem,so we didn't need either of them, Oh Well! It works perfectly and comes with two 15mm push in connectors. I fitted a plywood base and rubber mounted the pump, as it did not come with one. Any questions, just ask, can be picked up from Milton Keynes or sent by courier, happy either way.