The Starrett Metric Thickness Gauge is used in automotive, aviation, diesel and farm equipment manufacture and service and also in jig, fixture, gage and experimental work. These gages are Especially useful in adjusting tappets, spark plugs, distributor points, checking bearing clearances and gear play, fitting pistons, rings and pins and gauging narrow slots. Made in a wide range of types and sizes, each having from 6 up to 26 leaves ranging in thickness from .0015-.200" and 0.03-5mm thick straight or tapered. 13 Straight Leaves, 12.7x77mm, mm reading, 0.03-0.50mm Range.