Diaphragms are the moving part within the O2 Air Machine pond air pump and over time will stretch and can split, reducing the output of the air pump.
This Genuine replacement diaphragm for the O2 8000 Air Machine pond air pump from Pond One is made from a japanese silicone rubber for excellent reliability and life expectancy.
The flapper valve housing is the part that covers the diaphragm and it contains small rubber 'flapper' valves. Over time the flapper valves will wear and the pump can lose pressure. Replacing both the diaphragms and the flapper valve housings at the same time will ensur eyour air pump works to its full potential.