This cable is made up of loose tubes of high-strength plastic with each one filled with a water-blocking compound to protect the fibers. The strength member of steel wire is positioned at the center of the cable, sometimes with polyethylene (PE) coating if extra fiber numbers are. ALTOS® Loose Tube, Gel-Free, Double-Jacket, Single-Armored Cable Features and Benefits Gel-free waterblocking technology Craft-friendly cable preparation Corrugated steel tape armor Provides rodent resistance for direct-buried applications Flexible, craft-friendly buffer tubes Facilitate easy. Corning ALTOS® Lite gel-free, single-jacket, single-armored cables are designed for campus backbones in direct-buried installations. Loose. Fiber Optic Cable, Outdoor Arid Core Gel-Filled Tubes, Stranded Loose Tube Double Jacket, Single Armored. Engineered to deliver superior signal integrity over long distances while withstanding harsh environmental conditions, this type of cable has become a cornerstone in modern.