Product Feature Ignition Test Pen---This product can be used to test spark plugs, coils and distributors in two places, the electronic ignition system and the circuit breaker. The grooved end makes the contact area between the wire and the instrument larger. High-brightness bulbs and the observation windows make test results easier to observe. Usage---When the engine is started, place the grooved end of the instrument on the spark plug wire. If the bulb flashes, the spark plug wire is transmitting the spark Careful Design---Grooved end makes the contact area between the wire and the instrument large, ensure accurate test.With portable pen clip, easy to carry and store, bring much convenience for you. Professional Quality---Quality light bulb, high brightness, easy to observe, convenient to use.Stable characteristics, professional performance, high reliability.Conform to strict quality control standards, dependable to use. Product Specification Type Ignition Spark Tester Vehicle Type Passenger Vehicle Special Features Automotive Spark Indicator Voltage 12V Material Aluminum Length 12.2 cm/4.8 in Diameter 1 cm/0.4 in Product Weight 30g Package Included 1 x Spark Tester