●Ideal for cleaning gravel without losing the gravel. Suitable for any kinds of gravel.
●Patented two-way valve, following the narrow of the valve to draw out of the water and fill up your aquarium in ease with one tube.
●The design of wave edge of the suck-up bottle provides stable water flow when operation.
●Reliable quality of hose prevent harden with longer life.

Instruction:
●Connect the suck-up bottle with syphon hose and pump the rubber ball to makes the flow starts. Clean the gravel by water circulation inside the suck-up bottle, adjust the valves beside the rubber ball to control the water flow, than the sludge and waste can be sucked out magically. (hang down the balance of hose lower than aquarium, and now the narrow of the valve is directed out from the aquarium) 
●Remove the end hose to be connected to faucet, change the direction of the valves to fill up the water.

Tip: 
Two valves aside the rubber ball, which in opposite directions is stop the water draw in and out, in another word the water is only working in the narrows which are in the same direction.