["brand new and high quality\nFeatures:\nwe adopt 0.36in digital tube, suitable for 1~8 cylinder autos and motors 12V engine.\nOur products are with shells and shine brighter.\nDisplay battery voltage before and afrer engine start\nWhen 12V car battery over voltage (overvoltage) or undervoltage, it will be flashing alarm. \nWhen battery voltage is less than 11V (15V), it will flickering alarm and display the real battery voltage.\n\nSpecification:\nWorking Voaltage: 8v~17v\nWorking Current: 40mA\nVoltage Accuracy: ±0.1V；\nRotating Accuracy: ±30round/min\nMaximym Rotating Gauge: 100-31800round/min\nBulb Color: Red\nQuantity: 1 Pc\nOther Fixtures:\n1. This Auto car RPM meter 2 in 1 function meter use Ultra bright 0.36 inch digital tube digital display instrument, driven by high performance mcu. Can be used in automobile, motorcycle and other electronic ignition vehicles. Using high integrated design, the size and appearance of the same size as the single function of tachometer. Can be easily installed in the card into the supporting housing.\n\n2. Behind the instrument button is for adjusting internal parameters, when it is discovered that the display speed and actual speed inconsistency , then we need to adjust the parameters (motorcycle idle 1100-1600, idling 750-1200, engine idling in the just started on the high side, hot car stability decreased, such as conditioning load change will influence idle).\n Parameters depending on the type of engine (such as the horizontal bar, steel, four cylinder), distribution, and wiring position are concerned, specifically according to the parameters in more detail below as a reference. The parameter mismatch phenomenon is displayed, and the speed of the actual difference, are integer times or several times. This reset the normal parameters on it.\n Before installation, please kind carefully read the following details, problems timely and contact customer service. We are very happy to your answer to problem solving.\n How to adjust the rotate speed parameters if the real speed is different from the display speed\n long press button for more than 3 seconds to enter setting state, short press select frequency, long press more than 3 seconds to confirm , ,\nthen it is ok. The parameters are saved in the internal chip, even if the power cut and parameters donen'for t lost.\nthis meter default parameters is 2\n2.1 Parameters: adapt to the frequency of 8.33Hz/1000 RPM per cylinder ignition EFI car use.\n2.2 Parameter (the default setting): suitable for frequency 16.66Hz/1000 of four - cylinder EFI (second igniter) and two-stroke and four stroke motorcycles.\n2.3 parameters: three cylinder for cars for the use of frequency 25.00Hz/1000 rpm\n2.4 parameters: four cylinder for cars are suitable for frequency 33.33Hz/1000 rpm turn (with electric for cars) an igniter.\n2.5 parameters: eight cylinder for cars are suitable for frequency 66.67Hz/1000 rpm turn.\n2.6 parameters: six cylinder for cars are suitable for frequency 50.00Hz/1000 rpm turn.\n\n3. This meter displays car engine speed automatically. When car engine started, it begin to show the speed. If battery over voltage,which is bigger than 15V(>15V)\nThe meter display speed will be flickering and flashing, which is alarm. and notify you this car battery voltage is over. If enginer speed over 10000 rpm/for m, for example 15000r/min, the car tachometer will display -150\n\n4. Working Volt :DC 8V -17V\n Current :40mA\n Voltage accuracy: +/- 0.1V ;\n Speed accuracy: +/- 30r/min\n\n5. How to wire:\nBlack wire : Ground wire, connect battery negtive output (for DC - )\nRed wire: Power supply, connect battery positive output (for DC +)\nYellow wire : Speed signal cable, connet to ignitor outlet or trigger lines\n \n6. Installation guide :\n6.1 Please connect Red and Black wire in advanced to make sure display is normal to work then you connect other wire. Attention!\n6.2 The speed signal from the engine ignition signal, can have many wire connections\n 6.2.1 . Electronic tachometer wire (some car models have a on special wire for speed, if connect, will have the best quality signal)\n 6.2.2 The high voltage ignition coil inlet wire (if car have no special speed line, we advise connected here)\n 6.2.3 Ignition outlet wire\n 6.2.4 The ignition trigger inlet line\n 6.2.5 The trigger coil outlet\n\nBecause of each car line is not for always the same , above all wiring position may be varying degrees of interference ,result the speed signal is not stable,\nIf your car model have special electronic tachometer line,connect it and signal will be absolutely no problem,So best choice is 6.2.1\nif no have special electronic tachometer line, then connect high voltage ignition coil inlet wire is also good.So second choice is 6.2.2\nVery import Attention!!!\nNever connect singal cable to high voltage of high voltage ignition coil outlet wire. You will burn this auto car meter!!!\nNote: \n1.Please allow 1-3cm error due to manual