4in1 Li-Lion Battery Optical Power Meter Visual Fault Locator, Network Cable Test Optical Fiber Tester LED VFL ,Wide Measuring Range

HIGH PRECISION:the dynamic range is 80db, and the measurement error is less than ±0.2dbfc/sc/st interface is supported BUILT-IN LITHIUM BATTERY:Usb charging is fast, charging is safer and the power is longer STRONG RED LIGHT SOURCEShort press:VFLto switch VFL output mode. CABLE TESTLong press to turn on/off cabletest mode LED LIGHTShort press to turn on/off LED light