LTD-100 WL Motherboard Component Coil Tester With Light indicator and Audible Sound From Speaker. Function: Inductance Testing: It measures the inductance of coils on a motherboard. Functionality: It tests inductors by detecting inductance when brought into contact with the component on a powered mainboard. Indication: A working inductor is indicated by the LED light on the probe turning on and an audible sound from the speaker. Operation: The device has a simple ON/OFF switch for ease of use. Application: It's used for quick testing of inductors, likely in electronics repair or troubleshooting.