Although optical fiber has become a hot word at present, many related projects are also being implemented. However, due to technical level, universal demand and price factors, it is impossible for the optical fiber to be able to form a general demand for the time being in the market. The current network cabling products, copper is still the mainstream, ultra-five, six types of twisted-pair performance in all aspects more suitable for public needs, the scope of application is very extensive. According to statistics, Category 5 and Category 5 wire currently occupy the largest market share, but Category 6 wire and cable are expected to maintain their upward trend. According to this trend, Category 5 will temporarily maintain market share, while Category 6 will be gradually promoted in the future To the general public market, to meet the faster network transmission needs. In today's high-definition surveillance camera applications, fiber is one of the best ways to deliver the best bandwidth performance in any connection. The use of optical fiber, necessarily accompanied by the use of some accessories, the following optical fiber transmission layer can be used by several common accessories, a detailed introduction. In particular, look at the fiber closure. Fiber Jumper refers to both ends of the cable are equipped with connector plugs, used to achieve optical activity connection; plug at one end is called the pigtail. Fiber jumpers are similar to coaxial cables, except that they do not have a mesh screen. The center is a light-propagating glass core. In multimode fiber, the diameter of the core is from 50 μm to 65 μm, which is roughly equivalent to the thickness of human hair. The single-mode fiber core diameter of 8μm ~ 10μm. A core of glass envelope with a lower index of refraction than the core is surrounded by the core to keep the fiber in the core. Outside is a thin plastic jacket, used to protect the envelope. Fiber Optic Coupler is used to split or combine optical signals or extend optical links. It belongs to the field of optical passive components. It is used in telecommunication networks, cable networks, subscriber loop systems, and regional networks applicable to. Fiber closure is a passive component that provides good protection for fiber splices. Can be airborne assembly, pipe assembly and underground embedding. Fiber closure can accommodate 24 users and 144 splice points. It is used as a splicing closure and termination point for feeder cables and branch cables in FTTx network systems. It integrates fiber splice, splitting, distribution, storage and cabling in a solid protective box.