Plastigage is a thin strip of wax string that is temporarily torqued between the crankshaft and connecting rod or main bearings as a simple and accurate way to verify clearances. The wax string is compressed to show the amount of bearing clearance and then measured using the protective sleeve guide. Each sleeve contains a 12″ strip that can be trimmed as needed. Kit contains two strings measuring range .001″-.003″. Detailed instructions are included.