Docooler Portable Handheld Neon Tube Lamp Fluorescent LED Tester USE EASILYEasy to use just by pressing and holding POWER button, then LED indicator and the neon tube will flash. AA BATTERIESPowered by dry batteries, easy to use and carry. It is a great tool for repairing neon lamp.Powered by 4 * AA batteries (not included). APPLICATIONWith this tester, you can quickly find the reason why neon lamp does not turn on. CONVENIENCEPortable handheld neon tube.Works perfectly on neon tubes, small, lightweight and compact.Save your time and hassle. HOW TO USEInstall the batteries (pay attention to the polarity). Extend the antenna and touch it to the polarity wire of neon tube. Press and hold POWER button, then LED indicator and the neon tube will flash.