SainSmart Digital Transistor Tester Capacitor, ESR Inductance Resistor LCR Meter NPN PNP, Compatible with Arduino (Blue) Latest M328 version of the software ,more functions. Use 8MHz external crystal , better measurement accuracy. Backlight LCD display,only 2mA when stand by. Mainchip is the DIP, easy to DIY, update the mainchip. Using 9V battery.