Connects in-line between the spark plug and the ignition wire
Use to quickly troubleshoot ignition system with "hands-free" operation
Shows a duplicate view of the ignition spark
Technician can visually check condition of ignition system at each cylinder
Frequency and intensity of flash indicates whether there is an ignition system problem or a fault in the fuel delivery system
Flash can be seen in bright sunlight. Clear plastic body can withstand rough use and resists automotive chemicals. Protected by mechanical strain relief.