Checks the power level of all 1.5V and 9V batteries, including button cells. Universal battery checker tester compatible with AA, AAA, C, D, 9V and button batteries. Simple operation: place your battery between the two test points of the tester, and the easytoread, colorcoded meter indicates power level at a glance, showing instantly whether the battery is a dud or if you can squeeze out more life. Clear, colorcoded display provides quick, actionable information to help you decide which batteries to keep and which to discard. Reduces guesswork, helps save money, and minimizes waste by ensuring batteries are used only when they have sufficient power. Use scenarios: Home: quickly assess batteries from remotes, game controllers, and wireless devices to determine replacement needs. Office or classroom: test spare batteries for calculators, clocks, and remotes before use. Electronics hobbyist or : verify batteries pulled from devices or kits before reuse or disposal.