Simply screw onto the water tap and connect to the aquarium hose for partial water change. The water jet produces a suction effect that extracts water from the aquarium Connects with the hose that sucks water from the aquarium via the bottom cleaner (slime bell). Contents: 1 water jet pump with hose connector 12/16 The water jet produces a suction effect that extracts water from the aquarium Connects to a hose that sucks up water from the aquarium via the bottom cleaner (mud bell). Content: 1 water jet pump with hose connector 12/17