Catalog > Test and Measurement > Test and Measurement Instruments > Fluke Instruments Catalog > Test and Measurement > Test and Measurement Instruments > Special Function Testers > Miscellaneous Testers Fluke Fibre Optic Light Sources Fibre Optic Light Sources Test different cable lengths FLUKE FOS850 FIBER OPTIC LIGHT SOURCES Discontinued Specifications, Prices & Availability may change without notice. Images are for illustration purposes only. E&OE Overview A variety of light sources allow you to test different cable lengths.