Installation instructions: This instrument is not waterproof and must be installed in a dry, rain-protected location. Display instructions: This instrument features an LED light bar display. When the tank is full, adjust the potentiometer until all LEDs illuminate. When the tank is empty, adjust until all LEDs are off. Test instructions: After connecting the positive and negative power supply terminals, the meter will not light up. Connect the signal wire to the negative terminal; all LEDs will then gradually illuminate, indicating proper functionality. Adjustment instructions: Connect the black wire to the positive terminal of the 12V power supply, the green wire to the negative terminal, and the yellow wire to the oil float sensor signal output. Add oil to the tank, then slowly adjust the potentiometer until all ten LEDs illuminate. Important note: The signal wire must be connected directly to the oil float sensor. Any existing wiring between the sensor and instrument must be disconnected to ensure accurate readings. Note: This product is compatible only with vehicles where the oil sensor resistance is low when the tank is full and high when empty. Working voltage: DC 12V Wiring connections: Black wire: +12V (positive) Green wire: −12V (negative) Yellow wire: sensor signal input LED display: 1 red LED, 1 yellow LED, 8 blue LEDs Dimensions: 48 × 28 × 19 mm (L × W × H) Cutout size: 46 × 26 mm This meter includes an adjustable potentiometer and is not universally compatible with all vehicle oil gauge systems. The red LED indicates power supply status. The yellow LED turns off when no oil is detected. At 5–6 units, multiple LEDs illuminate simultaneously; additional LEDs light sequentially as oil level increases. This meter must be used exclusively with a compatible oil float sensor. It is not compatible with standard OEM oil gauges or scales. Color: Black Material: Plastic Package contents: 1 × 12V oil level gauge