Feeler gauges are must-have tools for machinists to ensure that gaps and clearances between parallel components are within specified limits so that machinery functions properly. Made of high carbon steel, this tool features 10 gauges that fold out of a sturdy metal housing and can be used independently or with several combined for different measurements. 4" Standard Feeler Gauge includes .0015", .002", .003", .004", .006", .008", .010", .012", .015" and .025" gauges. A plastic hang-up sleeve is provided for storage when the tool is not in use.