ZTT has the core technique and invention patent of producing submarine cables, whose products passed the state verification. ZTT submarine cable has established a whole production line of manufacturing optical unit, stranding cooper conductor, amoring steel tape/wire, cabling, stranding 24 drums and argon-arc welding, jacking with a dock of 5000 tonnages. ZTT reached of 5000km of ability in producing , storing and delivering cables in one year.