coating thickness gauge models: CM-8829FN, CM-8829S, CM-8828FN,CM-8855FN,CM-8856FN, CM-8821,CM-8822,CM-8823,CM-8825FN,CM-8826FN Application:used for measuring thickness and corrosion of pressure vessels,chemical equipment,boilers,oil storage tanks,etc.in industries of petroleum,shipbuilding,power station,and machine manufacturing. Model: CM8829 In built probe(s) Operating principle: magnetic induction/eddy current (F/NF) Measuring range:0-1250um/0-50mil Resolution; 0.1/1 Accuracy: ±1-3%n or ±2.5um Min. measuring area: 6mm Min. sample thickness: 0.3mm Battery indicator: low battery indicator Metric/ imperial: convertible Power supply: 4x1.5V AAA(UM-4)battery Auto power off Operating conditions:0-+45℃(32℉-104℉),≤90%RH Dimensions: 126x65x27mm weight: 81g(not including battery) Optional accessories: other range 0-200um to 15000um RS-232C cable & software: 1.USB adaptor for RS-232C 2.Bluetooth interface