This Powerbuilt Mechanic’s Stethoscope is great for diagnostic engine work and troubleshooting issues. Use this stethoscope to easily identify damaged valvetrains, bearings, transmissions gears, piston slaps, gaskets, and more. Includes two probes to pinpoint the source of a noise coming from faulty parts. Every package comes with professionally written usage instructions that take you step by step through proper tool usage.