Yea it sits underneath the tank, you have two hoses one for input and the other brings water back to your tank. Don't have pics but if you YouTube it you'll get plenty of results. I have the Fluval 306. You can get a Fluval 206, but if space is a premium go with the HOB
. I had the marineland penguin 200 before, but didn't like it, the filter pads would get gunked up in a week and then the water would go around it instead of through it.