KDT2649 Features: -Place probe on end with regular bulb to check low voltage.-Checks head lights, tail lights, turn signals and other circuits.-Tests for faulty sockets, connections and broken wires. Includes: -Place probe in end with neon bulb to check for spark voltage Tester includes 36" cable and shock proof case.. Specifications: -Checks 6 and 12 volt circuits for voltage and checks spark plug for spark.-6V and 12V Circuit and Spark Plug Tester. Warranty: -Lifetime warranty does not cover abuse.