The pumps combine a specially formulated diaphragm material for extended life and incorporate energy efficient motors for low power consumption. The design also includes low cost servicing which needs only a screw driver to complete. The pump has a compact alloy casing which is weatherproof and does not degrade over time. The diaphragm is electro magnetically operated, which eliminates sliding parts and keeps wear and tear minimal and power consumption low. Operation is only 40 dBA. A comprehensive range of models is available from Charles Austen offering flow rates in steps from 30 l/min to 200 l/min with an exceptionally long service life and 18 months warranty. Frost and rain proof the ET proves ideal for aeration in sewage treatment plants, hotel kitchens, industrial car washers and large scale aquariums. It is equally suited to interior use in odour neutralisers, spas/whirlpools and decorative water features.