A feeler gauge is used to measure or set very small gaps, normally under 1 mm. When the blades are folded back into the handle, the thin, delicate blade are protected. The thickest possible blade that can be inserted into a gap or crack shows its width.
Victoria Tool Library
http://victoriatoollibrary.org/
750 Fairfield Roadhttp://victoriatoollibrary.org/
Victoria, BC, V8W 2H1
Canada