- Comprehensive engine diagnosis: This spark plug tester works with small and large engines to check spark plug condition in cars, lawnmowers, motorcycles, and more. It helps quickly identify ignition problems and supports efficient engine performance. - Easy-to-use diagnostic tool: Attach the tester to the spark plug wire; the indicator shows whether the spark plug is firing properly. Simple testing saves time and helps avoid unnecessary repairs. - Broad compatibility: Suitable for internal combustion engines in vehicles and external engines in lawn equipment. A reliable tool for mechanics and professionals needing to inspect spark plug performance. - Durable construction: Made from high-quality materials for long-lasting use. The rugged design withstands harsh environments and heavy use. - Use scenarios: Car maintenance and troubleshooting; Lawn equipment service (lawnmowers, etc.); Motorcycle tune-ups and small-engine repairs.