A20 is the universal expansion tank ideal addition to the Aqua 8, Aqua F and all other types of pumps (for example Shurflo and Flojet).
The expansion tank eliminates the pulsating operation of the pump and supplies a constant flow of water in the required quantity.
It extends the life of the pump and boiler and cuts water consumption.
It is precharged at 0.9 bars (13.05 psi) but it can be charged with the special valve with a normal compressor, which allows it to be adapted to all pressure switch pumps. 
Supplied with 13mm  hose connectors and screws for fitting.