An additional oxygen supply is essential for many varieties of fish & aquariums. Fish only thrive in aquarium water with a well-balanced oxygen content: they display fewer signs of stress, & show deeper magnificent colours. In water with a higher temperature or a sparsely planted aquarium, an additional oxygen supply is essential. Filters & decorations can also be operated in conjunction with the Eheim Air Pump. The Eheim Air Pump at a glance: Very quiet operation Adjustable air flow level on pump; on pumps 200 & 400, the two air flow outlets are separately adjustable Fully equipped with new Eheim air vents & a 1m air tube, (200/400 include 2 air vents & 2 air tubes) Dimensions: 152 x 89 x 71 mm (Lx Wx H) Rubber suction pads to dampen vibration Hook for hanging vertically Technical data: air pump 100 air pump 200 air pump 400 Pump power 100 l / h 200 l / h (2 x 100) 400 l / h (2 x 200) Pump outlets 1 2 2 Power 3.5 watt 3.5 watt 4 watt Please note: This device is designed for use in Germany & thus comes with a power adapter for use in the UK. What’s this?