Simply select volts, ohms or current and the Tester does the rest. FLUKE Voltage, Continuity and Current Testers automatically measure volts AC and volts DC with precise digital resolution. Choose from 600V (No. 51577) and 1000V (No. 51578). Features easy and accurate OpenJaw™ current measurement and continuity beeper. Rugged, compact design with probe storage resists a 10' drop. Detachable Slim-Reach™ probe tips are customized for national electrical standards. Auto off conserves battery life. Two AA zinc chloride batteries included. Custom Holster (No. 51612) for both models conveniently clips Tester to your belt, sold separately.