Small and portable: small AA battery tester (BT-168D), compact and lightweight, easy to carry. Works without batteries: easy to read, numbers indicate power level. No batteries are needed. It is activated by the battery under test. Test Different Types of Batteries: The battery tester is suitable for standard and rechargeable household batteries. AA, AAA, C, D, 1.5V, 9V, button cell battery tester. This product is sold by ZVD Store Battery Saving: You can easily test the battery voltage to determine whether the battery capacity is low or high, which prevents us from wasting a perfect battery by throwing away a good battery. Easy to read: The portable device design is easy to read: the battery voltage is displayed on LCD screen.