Top-It-Off Deluxe kit for the Do It Yourselfer. Comes with three float switches, relay, project box, instructions and more. Included are two acrylic brackets to secure it to your sump with silicone or glue, as well as a few gel-filled snap connectors.
Use the same kit I use for my 400g's evaporative needs.
Here's my experience installing it to provide some visuals: installing-aquahub-ato-kit
You will need a short extension cord, some tubing and a powerhead or pump. Everything else is included in the kit.