1. The air strength rate is adjustable free by the turning the bottom round. 2. Smart design comes along with advance air-compressing system. 3. Adopt artificial rubber that keeps a steady air output and pressure. 4. Low power consumption and super silence operation. 5. One or more air stones can be connected to the pump outlet with a pipe & air divider. 6. Suitable used for air supply for aquarium water ball light, etc.