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.

Feature and Benefits:

• 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)