The Eheim Pro 3 is an exceptional filter that does come with a hefty price tag. Of course these days what doesn't. There is a difference with the Pro3 is you are getting your moneys worth and then some.
There is a sweet 450GPH output with this filter which is plenty for my 75Gallon mixed reef setup. The filter is rated up to a 320Gallon aquarium. There are 2 inlet connections and a single outlet. This allows for water to be filtered from opposite ends of the tank which is something I was missing with a single inlet canister filter. You can also manually adjust the water flow to a desired amount.
This filter features an in-line heater that heats your water as it enters/exits the filter and is set via a LCD display screen. This ensures your water temp is exactly what you want it to be.
Included in the box is everything needed to get your filter up and running; spray bar, almost 15feet(14'9") of tubing, a drip tray, safety clamps, all necessary fittings, 1 coarse filter pad and 1 ehfisynth fine filter pad. The physical dimensions of the filter are: 12" x 12.75" x 23".
This has been the best filter I have owned and will look no further than Eheim for all of my future filter needs. Probably the best feature of all is the low consumption of power that will reduce the electricity my previous filters were using. This single filter replaced 2 other canister filters and 3 heaters in the tank. I would/will be highly recommending this filter to all of my family and friends.