Specification: Item Type: Digital Timing Light Material: ABS Operating Voltage: 12v Timing Adjustment: Correct timing in turn helps ensure that your engine is operating with power and efficiency. Ergonomics: Handle pistol design conforms to engineering design, comfortable keys, good hand feel, easy to operate. Material: High strength, impact resistant ABS housing, replaceable clips. Digital Display: Digital display button operation panel, simple to operate Universal Fitment: Suitable for cars, motorcycles, individual boats, saloon cars, boats, aircraft, club cars, lawn mowers and other 12V batteries. Guide: Accurate ignition timing lights are necessary to get the best fuel economy and performance from ignition engines, and your timing provides a convenient way to use engine timing in today's cars. Advanced timing and other auxiliary functions, allowing the user to check the vacuum, mechanical or computer controlled timing curve! Usually, the engine needs to be adjusted or checked by a specific vacuum with a vacuum pick suitable for distributor or engine mounted in a car, at a specific engine speed or in some cases. Plastic timing can be used in 6 volt or 12 volt positive or negative grounding systems. 12 volt positive grounding system: 1. The timing, etc. red test is sandwiched between the positive terminal of the 12-volt battery. 2. The black of the timing lamp is connected to the negative terminal of the 12 volt electron. 3. Use a jumper wire (minimum 18AWG in seconds) 4. The black clip is connected to the negative battery terminal. 5. Connect the red clamp to a safe engine ground wire, e.g. alternator bracket/engine body. Package List: 1 x Digital Timing Light1 x User Manual