Koi Air is a reliable way of supplying aeration to ponds and filters. Koi Air 25Koi Air 25 has an output of 25 litres per minute and comes with an 8 outlet chrome manifold and spares kit.Koi Air 50It has an output of 50 litres per minute and comes with a 12 outlet chrome manifold and spares kit. Koi Air 65It has an output of 65 litres per minute and comes with a 14 outlet chrome manifold and spares kit.You may also find the followinfg products useful when purchasing this item:Silicone airlineAirstonesNon return Valves