Don't understand you question. You open the tank fuel fill hole and glue in the potentiomenter. Attached to the pot shaft is a 90deg elbow. Attached to the other end of the elbow is a short rod. Attached to the other end of the rod is a float. All these items are scaled to the size of your tank. You attach two wires to the pot and use a voltage divider to measure voltage. That's how virtually all car fuel tanks are measured. It's simple and accurate.