NA-450DOUBLE OUTLET AIR PUMP, WITH ADJUSTABLE KNOBHas 2 separate connection outlets, therefore can be adjusted faster and more conveniently, the chosen adjustment remains permanently, without the need to readjust.Features• Modern compact design.• Simple setup and operation, quick start.• All models come with rubber feet, to avoid vibration.• Very quiet motor operation and reliability.• Full instructions and setup tips.• Please remember to use a check valve or non return valve.