Keep a variety of leaf thicknesses on hand to confirm gaps are within tolerance.

To ensure accurate readings, these sets come with a certificate of calibration traceable to NIST that states they’ve passed a test for accuracy.

To measure thickness in areas where standard feeler gauges don’t fit, these sets have leaves with narrow ends.

These sets combine a wire gauge, a tapered-width feeler gauge, and a set of feeler gauges for tight spots in one tool.