Regular hose connection. But push button for 30 seconds of water. Then push again and again and again. But filled my 64 gal. tank pretty quick considering.

The fresh water uses a regular garden hose connection. Problem is, you get 40 seconds of water per button press, so you do have to stand there and repeatedly press the button. If you want to hook into the non-potable rinse connection, it's trickier. They typically have a male threaded connection of a smaller size. Sometimes that's cut off entirely, and you'll need a small barb to connect onto the cut-off hose.