This Complete Kit for 1 acre ponds Includes a 1/4 Hp Rocking Piston Air Pump in a cabinet, a 2 way manifold with a pressure gauge, two 100 ft rolls of 3/8" weighted tubing, and two 9 inch diffusers with bases The manifold includes an oil filled pressure gauge to reduce indicator vibration. Also attached is a pressure relief valve which opens at approximately 17 psi to prevent damage to the compressor The self-weighted air hose is very heavy duty and pliable. It is stronger, thicker and heavier than other brands. It will not crush or kink and can handle freezing temperatures The air diffuser bases allow you to place the air diffusers firmly at the bottom of the pond and keeps the air diffusers up out of the mud The 9 inch EPDM disc diffusers are designed for industry heavy duty installation and offer the lowest back pressure in the market, only adds less than 6 inches of water depth back pressure, allowing you to utilize your air pump in the most efficient way This complete aeration system includes a 1/4 hp rocking piston compressor and it is built into a heavy duty cabinet. The locking cabinet is landscape green color and designed for outdoor extreme weather conditions. Within the cabinet we have added a cooling fan with cross flow ventilation. All components are protected within. The heat protection hose leads externally and all you have to do is connect your air hose. Very simple to install and operate. The manifold includes an oil filled pressure gauge to reduce indicator vibration. This gives a more accurate reading of the actual psi of your system. Also attached is a pressure relief valve which opens at approximately 17 psi to prevent damage to the compressor. The gang valves are high quality brass with 3/8" barbs connectors. A short section of heat resistant hose is included so as to reduce heat to your air hose connection. All high quality components and very nice design. The self-weighted air hose is heavy duty and pliable. It is stronger, thicker and heavier than other brands. It will not crush or kink and can handle freezing temperatures. It is ideally suited for rugged installations of aeration systems in ponds, reservoirs or lakes. This kit contains 2 3/8" 100 ft rolls The air diffuser bases allow you to place the air diffusers firmly at the bottom of the pond and keeps the air diffusers up out of the mud. The air diffuser base is designed with a hollow base that can be filled with sand or gravel. The 9 inch EPDM disc diffusers are designed for industry heavy duty installation. Precision perforated I-shaped slits open when airflow is present and close when airflow is stopped, which increase the slits resist from tearing, and stay cleaner longer. These diffusers offer the lowest back pressure in the market, only adds less than 6 inches of water depth back pressure, allowing you to utilize your air pump in the most efficient way.