Fiber Optic Cable Spool

Kilometres of glass strands wound on a single drum/Technology

A standard fiber optic cable spool holds 2 to 4 km of cable containing multiple glass fibers, each thinner than a human hair. Light signals inside these fibers can carry terabits of data per second over hundreds of kilometres with minimal loss. The glass core is typically 9 micrometres in diameter for single-mode fiber.