Hakko Air Pumps are sleek in design. It is a relatively small unit with surprisingly high output. The Hakko air pumps are built to last with a very durable body and mechanics meaning years and years of everlasting quality airflow. Hakko air pumps utilize linear- motor theorem to reduce power consumption during full operation. Units are extremely quiet utilizing spectrum analysis technology in order to decrease any mechanical noise. No oil needed for lubrication making the Hakko easy to maintain. Adding an air pump to your pond system will help increase levels of healthy bacteria, lower algae levels, and help create and maintain a healthy eco-system. Air pumps are recommended for all pond sizes. UL and CE listed for outdoor use. 2 year warranty. Available in six sizes; Hakko25 - 21 liters per minute, 17w, 3.7 psi (32dB) Hakko40 - 51 liters per minute, 40w, 5.5 psi (35dB) Hakko60 - 68 liters per minute, 63w 6.7 psi (38dB) Hakko80 - 86 liters per minute, 85w, 7.8 psi (38 dB) Hakk Hakko Air Pump Hakko 25 Air Pump