The Blagdon annual service kit includes all likely parts to service your koi pond air pump
Contents:
1 x Intake foam seal
1 x Intake foam
1 x Cover lid seal
1 x Outlet foam seal
4 x Flapper valves
2 x Diaphragm front boards
2 x Diaphragms
2 x Diaphragm back boards
4 x Diaphragm protective teflon washers
1 x set Outlet Foams set of 3
It is recommended to change these items annually. Diaphragms should be changed when they become worn.