Working Time:about 2 Hours Of Continous Useprobe Warm Up Time:about 25 Secondsbuilt In Metal Detectorwith ‘beep’ Sound Indicator This Tester Is Designed To Distinguish Diamond Moissanite From Other Fake Stones Quickly. It Has Fine Elastic Tipped Probe For Testing And Able To Identify Stones As Small As 2pt. Easy Operation Without Necessary To Adjust Led Bar Garph Via Volume Control To Match Stones Of Different Sizes Like That Used In Other Diamond Tester Models Could Be Powered By Aaa Batteries Nimh Batteries Or An Ac Power Adaptor not Included In The Set Can Distinguised Stoned As Small As 2 Pt Low Battery Detector Equipped With An Elastic Probe Tip Built In Metal Detector Automatic Power Off With ‘beep’ Sound Indicator Rubber Paint Finish Factory Calibrated Specifications: Working Voltage: Dc 4.5v Aaa Batteries Or Ni-mh Battery Or Ac Adaptor 110240v Dc 4.2v not Included In The Set Probe Warm Up Time: About 25 Seconds Working Time: About 2 Hours Of Continous Use Net Weight: 65g not Including Batteries Tester Size: 173 X 42 X 22mm l X W X D Working Temperature: 18 30c Set Includes: 1 X Diamond Tester 1 X Testing Base English User Manual Carrying Case Standard Factory Package