The back side of this gauge has an inlet/outlet fitting to bring air into the panel and out to the air bags. The gauge has a small bulb pre installed that can be wired to a +12v power source. Route the opposite lead to a ground. You can use a toggle switch in between the ground bulb connection and ground connection to turn it on/off.
The front of the gauge features a built-in paddle valve which will inflate/deflate the bags as you move it up and down. The gauge to the left of the valve allows you to keep an eye on the bag pressure. This unit is very simple to setup and most of your time will be spent deciding on the best place to mount it.
Fittings / Air line
The Air Management Kit comes with the necessary fittings and air line needed to connect this panel to the bags and the air tank.
If you have already installed a horn kit or onboard air system on your vehicle, chances are that every port on the tank is already being used. A 1/4" run tee fitting is included for this reason, so that you may tee off one of the existing ports and add another fitting for the air management kit. The image below shows how can use the tee to add another fitting to a single port.