Filter question

[totalbiz]

I found several posts on ebay which are described as "External hang on filter box". It looks different though from a hang on the back filter. There are up to six compartments in a horizonal format. It almosts looks like a hang on the back sump. Has anyone found these useful?

 

[lapin]

While it looks external, if you look close at one of the pictures of it running it is hanging on the inside of the tank. It also has a pump hose attached to it. It does have some over and under water movement between baffles. Im sure it works.

 

[totalbiz]

While it looks external, if you look close at one of the pictures of it running it is hanging on the inside of the tank. It also has a pump hose attached to it. It does have some over and under water movement between baffles. Im sure it works.

You are absolutely right! Why would you want to put something of this size "in" you aquarium?