This is a multi-functional IC transistor tester with LCD digital display, specially designed for the maintenance personnel. You can choose different test modes, such as 5V mode, 3.3V mode and auto mode, to test 74CH series, 74LS series, CD4000 series, HEF400 series, 4500 series, operational amplifier, interface chip, optocoupler, automatic transistor recognition, voltage regulator tube recognition, etc.