Identifies compression stroke
Whistle Alert (Rigid)
No More Burning Fingers and Hands! Just Listen for the Whistle to Find the TDC Compression Stroke.
The Whistle Alert (Rigid) screws into a spark plug hole to quickly indicate compression stroke.
- Eliminates the need for an extra hand
- After installation, your hands are free to complete the job
- Excellent for use on deep, recessed spark plug threads
- Flexible model also available (#7894)