[Rob Petrie E395]

The isolater and line are assembled and filled with antifreeze and capped with a steel cap from the factory. The gauge has to be filled and comes with a little bottle with what I would describe as a plastic needle. You set the gauge on its face and fill the insides using the plastic bottle/needle deal. Through the port on the back where the line threads on. Then you run the line into the car. Remove the cap on the line and install it on the gauge.