Characteristics 1. The product is porous rubber hose with good softness, and any shapes required can be established. 2. It's bubble disperse equally and oxygen supply is excellent. 3. Suitable to be used for decoration and oxygen supply in all kinds of aquarium. Directions 1. Firstly connect rubber hose to the topping valve outlet with Ø4mm air tube, then connect it to the air pump with 4mm air tube and steep it into the water. once power on, equal bubble can be dispersed immediately 2. After being used for a long time, the holes on the surface might be blocked immerse it in hot water for about 8 minutes, then use brush or cloth to rub the surface slightly. 3. Proper-size air curtain can be chosen and the shape can be changed as you like.