These are professional standard external filters designed and built for the modern aquarium. They are an intelligent design conceived to make the most of the space beneath the aquarium or even to side of the aquarium in some situations. As with all of the Hydor product ranges careful emphasis has been placed on the power consumed to the power output ratio. Many filters offer great pumping power (lots of pumping power is not always needed it just sounds good and looks good on the box) but the Hydor filters only consume small electrical power making them efficient and cost effective. Not many filter brands can offer the same maximum performance and extraordinary versatility with a power usage starting at just 14 watts for the 150 model and only reaching 19 watts for the 600 model. Each model has special safety locking mechanisms to avoid any leaks. They have specially designed flow through and pump mechanisms to make them silent running. The clever positioning of medias and containers mean there are never any water bypass areas, meaning all water entering the filter is filtered. Each also has a ceramic shaft which ensures long life. And of course each comes with Hydor’s 2 year full RTB Warranty Also in its clever design it incorporates an easy to use priming pump. Gone are they days of sucking pipes and mouthfuls of dirty aquarium water to start the flow. The Hydor Professional filter range are perfect for all aquatic enthusiasts due to its features designed for professionals and beginners. Features; All filters are designed for maximum filtration size. All have easy priming pumps. Space Saving. No water bypass. Ceramic long life shaft. Large filtration areas. Silent running. Safety Locks.