This Hot Cam piston tool is designed to stop the piston in order to find top dead center 10, 12, and 14 mm increments that thread into the spark plug hole for accurate use

Included Items:
(1) 10mm-1.00 x 5 7/8 in. long black aluminum piston stop
(1) 10mm x 6mm black aluminum spacer
(1) 12mm-1.25 x 5 7/8 in. long black aluminum piston stop
(1) 12mm x 6mm black aluminum spacer
(1) 14mm-1.50 x 5 7/8 in. long black aluminum piston stop
(1) 14mm x 6mm black aluminum spacer