Find TDC (top dead center) with the in.whistlein. quickly, easily, and precisely every time! As the piston rises in the cylinder, compressed air escapes through the whistle. When the Whistle stops, the piston is at TDC. It's that simple! Dual thread pattern (14mm and 18mm) with attached 22in. hose fits most engines. Attached extension reaches into tight access areas.
