I originally bought one for my axolotes tank because they do not like heavy water movement it destroys their gills. It was perfectThe filter is super quite and flows really well. The water flow is actually really staedy through the filter. The suction holes are on the bottom so it can be used in a tank or terrarium with just a few inches of water. I Then removed it and tried on my fry tank. Still worked great. The little pump is great because it draws the water up through the botton and then pushes it up out the flow spout. So if the included filter insert is not enough for you, you can stick a piece of sponge filter in it to make it work even better. You can hang it from the aquarium edge with the included adjustable back hanger. It also has 2 nice suction cups on the back. The work really well I almost wanted to take them of and use them for a heater I have instead lol. I chose to use the suction cups instead of the hanger. Both functioned properly so its a matter of preference.When the item first arrived I was a little skeptical. It look basic and nothing special. I am glad I was wrong. When the filter arrived I opened it and noticed a fine black dust all over the filter. With it being white it made it look dirty. I then realized it wasnt dirty the filter that comes with it has carbon in it. It was just the carbon dust that is on most filters. After I quick wipe down with a paper towel it was perfectly fine. Before using the included filter insert make sure to wash the filter with tap water for a few second to remove the excess carbon dust. Most filter inserts you buy say to do this anyways.It you need a small filter for low water movement or small fish, go with this one. For the price you'll be happy.