Requires no battery to operate - easy to read, number indicates power level. No batteries required.It is battery activated being checked Testing Related Battery Types - The Battery Checkerboard Tester works with both standard household and rechargeable batteries. Battery tester for AA, AAA, C, D, 1.5V, 9V and button type Perfect for home use - great little tool can tell you if your battery is good, low or needs replacing.A must buy for anyone who regularly uses regular or rechargeable batteries Features Small portable - simple yet effective AA AA AAA battery tester checker (BT -168D), compact size and lightweight, easy to carry Testing Battery Types Related - The Battery Checkerboard Tester works with standard household and rechargeable batteries. Battery tester for AA, AAA, C, D, 1.5V, 9V and button type Requires no battery to operate - easy to read, number indicates power level. No batteries required. It is activated by battery being checked Perfect for home use - a great little tool can tell you if your battery is good, weak or needs replacing. A must buy for any person who regularly uses regular or rechargeable batteries Saving batteries - You can simply test battery voltage to determine if battery capacity is low or high. It will not directly detect battery capacity accurately. This will prevent us from wasting perfectly good batteries by throwing good -Black color -Material: plastic -Small size Package Included: 1 * Battery Tester (Batteries not included.)