The black box in the middle of the optical cable

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The tiny cylinder on the cable goes by a lot of names, such as ferrite bead, ferrite core, ferrite choke, or EMI filter. Electric company is bringing 1Gbps fiber optic internet to my area, and I'm hoping to have it completely installed in the next month or two. The fiber optic cable core is the physical glass medium that transports optical signals from an attached light source to a receiving device. I understood the low, fat black cable to be data cable, strung low because it isn't a severe electrical hazard.

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