The DeFelsko PRBFNGS-D PosiTector 6000 Cabled Very Thick Coatings Probe FNGS Only, Measures Coatings on Ferrous & Non-Ferrous Metals, 0-2.5" is ideal to measure very thick coatings on all metals. Ideal for measuring ship hull coatings and thick in tumescent paints. The PRBFNGS-D measures up to 63.5 mm (2.5 inches). It measures non-conductive coatings on both ferrous and non-ferrous metal substrates. Certificate of Calibration (Long Form) traceable to NIST or PTB included with every probe.