Using electromagnetic wave technology to measure wood moisture accurately, this meter has no pins, so it won’t damage wood surfaces. In shallow-scanning mode (1/4"), it tests wood 5/16" to 3/4" thick; deep mode (3/4") is for stock 3/4" to 1 3/4". This lets you scan boards of varying thicknesses, or read thick lumber at the center as well as at the surface to identify moisture gradients typical of case hardening.