The Extech CG204 is a portable non-invasive coating thickness meter with automatic detection of ferrous and non-ferrous substrates. The tester uses dual technology to indicate ferrous substrates (magnetic induction measurement) and non-ferrous substrates (eddy current measurement). It can take continuous and single measurements and operate in direct or group work mode. It has a memory for 400 readings and user-programmable alarms with threshold and maximum value. The CG204 includes two AAA batteries, USB cable, software, calibration iron, calibration aluminum, precision standards, carrying case and user manual.