Installation instructions: This instrument is not waterproof and must be installed in a place where it cannot be exposed to rain. Display instructions: This instrument displays an LED light bar. Fill Up the for Tank, adjust the potentiometer until the led meter all bright , and until don'for t have any oil in for tank adjust the meter led all crush out. Test instructions: After connecting the positive and negative poles of the power supply, the meter will not light up. Connect the signal line to the negative pole and all the meter lights will slowly light up, indicating that the meter is good. Adjustment instructions: Connect the black wire to the positive pole of the power supply, the green wire to the negative pole of the power supply, and the yellow wire to the oil float signal wire, then add more oil, and then slowly adjust the adjustable resistor so that ten lights just light up. Important note: The signal wire must be pulled directly from the oil float, and the wire connected to the instrument assembly must be cut off, otherwise the oil gauge will be absolutely inaccurate. Note: This product is only suitable for cars with low resistance when full of oil and large resistance when empt. Working voltage: for DC 12V connect cable: Black: + 12V positive Green: -12V negative Yellow: sensor singnal input LED display :one Red ,one Yellow ,eight blue Dimensions: 48x28x19mm(LxWxH) Cutting Size: 46x26mm this meter have adjustable potentiometer , it can'for t the same use with car oil scale. Red light is power supply Indicator light ,the yellow Turn off mean no oil , 5-6 is bright together the other one by one bright. Must cooperate with oil sensor (float).Cannot be used together with the oil scale. Colour:black Material:plastic Package Contents: 1 x 12VUnversal Motorcycle Car Oil scale meter LED Oil Fuel level Gauge Indicator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.