Steady Output: Max Air Flow Rate: 30 GPH; Pressure: 0.016 MPa; Power: 2.5 W. Perfect for aeration in 5 - 30 gallon small fish tanks and ponds. Adjustable Air Flow: Feature a rotary knob to control the amount of air for output, allowing for your desired air flow to fully oxygenate your aquariums. Quiet Operation: The pump emits 25 dB sound under the “Low” mode and maximum 40 dB noise like the hum of a refrigerator under the highest air flow. 1 Air Stone Disc: Produces lots of dense medium bubbles bursting into the surface of water steadily. A great way to aerate your tanks and enliven the aquatic life. Pump Accessories: Include 1 air stone, 3-foot airline tubing, 1 check valve and 2 connectors. Complete accessories to build the basic aeration setup in your tank. You are purchasing a high quality compact air pump which is suitable for use in any Freshwater or Marine aquariums. Designed to oxygenate your aquarium efficiently and quietly with its low power consumption and advanced air compressing system.

The Pump Set comes with a 3.2 ft airline tubing, 1 air stone, 1 return valve and 2 connectors.

ABOUT QUIET. LET US FACE THE TRUTH.
We have tested UL25 air pump to work on lowest flow rate, it sounds 25 dB, which sounds like Rusting Leaves, Ticking Watch.
On highest flow rate, it sounds 45 dB, which sounds like Quiet Whisper at 2 ft., Park.
This model has an adjustable valve - means you can adjust the air flow rate.
Sitting on a folded cloth to make it quieter.

Specifications:
Recommended Tank Size: 10 to 30 Gallons
Voltage: 110~120 V; 50/60 Hz.
Exhaust: 2 L/min
Pressure: 0.016 Mpa
Power: 2.5 W
Internal diameter of Airline: standard 4 mm
Length of the power supply cable: 6 Feet
Dimensions: 4.5 x 2.7 x 2.3 inch
Weight: 1 pound

HOW TO SET UP:

Cut the tubing to the required length. Connect the tubing to the pump and your air stone. Plug in. Simple.
Just ensure to set the pump higher than the tank. If not possible, use a check valve to stop any water flowing back from the tank to the pump!