Dealglad 200mm Foldable Feeler Gauge Metric Gap Measure Tool 0.05 to 1mm 20 Blade Every blade with its thickness clearly on it, easy to select Also easy to return when you don't use Ideal for feeler gauge valve shim use and metric gap measuring between two items or parts. It contains 20 blades, from 0.05mm to 1.00mm. The blades are made of high quality carbon steel.