The Oase AquaSkim 40 skimmer is ideal for the removal of free floating surface debris, such as leaves, uneaten fish food, pollen etc. The AquaSkim 40 is ideal for use with any duel inlet range of pond pumps. It’s highly stable due to the large base for weighing down with rocks and is connected to the pump with its 1-1 ½ inch multi stage hose tail adaptors. Recommended Flow Rate - ( 4000 to 16,000 litres )