CDI-511-9764 Inline Spark TesterIdeal for personal watercraft. Sealed design is an added safety factor that further reduces the possibility of igniting gas fumes, especially in the hull of a PWC. Good for checking spark on running engines.Features: Inline Spark Tester; Sealed design reduces possibility of fire; Can be used inline to the spark plug or connect to the engine ground for cranking speed test; Replaces: 511-9763; 511-9764;