In a compact, sturdy plastic rewindable dispenser case. Rewind feature permits retracting thinner feeler stock into the case, preventing damage. Made of the finest tempered steel. Marked every 6" or 150 mm with a line, thickness in thousandths of an inch or in hundredths of a mm (exception No. 666-1/2/cat.no. 52797). Case provides the ability to snip off the desired length without any waste. For adjusting tappets, spark plugs, distributor points, checking bearing clearances and gear play, fitting pistons, rings and pins, and gaging narrow slots.