EM281 is the battery tester Plugs directly into cigarette lighter. Displays information about electrical system, alternator orgenerator, voltage regulator.Ideal for use on your aircraft, car,truck, RV, and boat. Works on 12V/24V systems.SpecificationsLCD displayLCD backlight, Use as night light or map light (EM281A)LED indicators show the condition of the battery Automotive battery tester
