I run my 4+ by sitting it on the bottom of the tank which means it is several inches under the water before it gets plugged in. There is a lever under the outlet tube that you can use to adjust the flow and the outlet nozzle can be pointed through a range of about 90 degrees. There is also an attachment that can be used if you want bubbles in your water. It uses a venturi effect to pull air through a piece of airline and there is a small throttle device that goes on the other end of the air line to adjust how many bubbles you get. I have not used that venturi since about 15 minutes after I started using the filter because I found the bubble noise irritating. I just removed it and put it with my surplus parts pile from that and other filters. The air throttle eventually came in handy as a muffler when I wanted to bleed off some excess capacity from an ordinary air pump.
