This Faithfull Battery Tester is simple and easy-to-use on most types of standard domestic and rechargeable batteries. It helps to ensure the batteries are fully charged and ready for use. A simple analogue needle display indicates the power level of the batteries (good, low or replacement required). An adjustable arm allows the tester to accommodate the testing of D, C, AA, AAA, 9V 6F22 and 1.5V button cell batteries, and folds down for easy storage. Features: Analogue needle indicator. Tests D, C, AA, AAA, 9V 6F22 batteries. Tests 1.5V button cell batteries. NOTE:The tester is activated by the battery being checked. Keep test time as short as possible to avoid unnecessary battery drain.