The TEKTON Battery, Bulb and Fuse Tester tests voltage of AAA, AA, C, D, 9-Volt and button cell batteries. It can also test the continuity of standard appliance, household, automotive and decorative light bulbs. In addition, it can test the continuity of glass-type and blade-type fuses. Battery capacity is accurately checked under simulated load conditions. It will help you reduce waste and save unnecessary expenses by checking batteries, bulbs and fuses before replacing them. The analog meter is easy to read. Requires 9-volt battery which is not included.