CDI-511-9766 Spark Tester Enclosed 8 Cyl., adjustable spark gap tester. Has heavy-duty wire for mounting in any position. Helps reduce possibility of igniting gas fumes Adjust from 18 in, 14 in, 38 in and 12 in. Requires you to use your existing Spark Plug wires Features Spark Tester For Extension Wires, See 511-9903 Sealed design reduces possibility of fire Can be used to test 1-8 cylinders Replaces 850439 850439T 850439T 1 91-850439 California Residents WARNING Cancer and Reproductive Harm - P