Duoyi DY30-2 Digital Insulation Resistance Tester, also known as a megohmmeter.
It is a multi-voltage tester with settings for 500V, 1000V, and 2500V.
It is used for measuring insulation resistance up to 20 GΩ.
The device can also measure AC voltage up to 600V.
It features a digital display for easy reading and is suitable for various applications in industrial, commercial, and residential settings.