Overhead Optical Cable (GYTS) The structure of GYTS optical cables involves embedding single-mode or multi-mode optical fibers within loose tubes made from high-modulus polyester material, with the tubes filled with a water-resistant compound. A related GYTA type cable is available. The loose tube stranding technology make the fibers have good secondary excess length. Full specifications, samples and bulk pricing on request — we typically reply within 24 hours. GYTS is the outdoor fiber optic. Among the various fiber optic cable types available, GYTS (Central Tube, Steel Wire Armored) cables stand out as a popular choice due to their exceptional performance, durability, and versatility.