Fangrui Product Details It Uses Type-c Interface, Built-in Battery, Rechargeable, And Replaceable Probes. Three Test Methods: Plug-in Test Pad, Patch Test Pad, Probe On/offline Test. Probe On/offline Test: Online Test After The Motherboard Capacitor Is Discharged, It Is Strictly Forbidden To Test When The Motherboard Is Powered Off, And The Optocoupler Can Also Be Disassembled And Tested Offline. Patch Test Pad: The Maximum Testable Patch Optocoupler Is 7.6 (excluding Pins)x3.6mm, And The Minimum Testable Patch Optocoupler Is 3.8 (excluding Pins)x2mm. Applicable To 4-pin Optocouplers, Other Types Of Optocouplers Are Not Applicable For The Time Being. Note:this Product Is Only For Professional Electronic Maintenance Personnel. People Who Do Not Have Professional Electronic Knowledge Should Not Buy And Use It! After Many Hardware Updates And Parameter Modifications, The Current Generation Is Very Easy To Use. As Long As The Indicator Light Flashes, The Optocoupler Must Be Good. Since There Are Many Types Of Peripheral Circuits O