The UNI-T UT343D is a precise thickness gauge for professional applications in automotive and industrial sectors. This device accurately measures paint and coating thicknesses from 0 to 1,250 μm (micrometers) with a maximum accuracy of 0.1 μm, enabling reliable detection of repaired damages, repainted areas, or replaced components. It features dual-sensor technology: a ferromagnetic sensor uses magnetic induction for steel surfaces with a guaranteed tolerance of (±3 % + 1) μm and a minimum surface radius of 1.5 mm, while an NF metal sensor employs eddy current for non-ferrous metals with a guaranteed tolerance of (±3 % + 1.5) μm and a minimum surface radius of 3 mm. The device measures critical base layer thicknesses up to 0.5 μm for ferromagnetic surfaces and 0.3 μm for non-ferrous metals, with minimum measurement areas of Ø 7 mm and Ø 5 mm, respectively. Main applications include automotive paint inspections to detect accident damage repairs, verification of protective coatings on ships and marine structures, as well as quality control of various paint and coating layers on industrial equipment. The UT343D provides automotive dealers, vehicle inspectors, and industrial maintenance professionals with a reliable tool for assessing coating integrity without visible surface indicators. Its measurement capabilities help identify deviations in paint thickness that may indicate previous repairs or compromised protective layers. The device operates with simple functionality and delivers consistent measurements for both ferromagnetic and non-ferromagnetic substrates within its extensive measurement range. This successor model of previous thickness gauges maintains UNI-T's focus on measurement precision and operational reliability for professional environments that require accurate coating assessments.