Fiber Optic Splice Closure is the scientific name for fiber optic splice closures, which can also be referred to as fiber optic splice closures, barrels, and fiber optic splice closures. The fiber splice box is a passive device that provides a reliable guarantee for the connection of the fiber. Optical fiber junction boxes are widely used in network systems, CATV cable TV, fiber network systems, etc., and are indispensable components of fiber-optic communication networks. Fiber Optic Splice Closure is divided into an overhead, pipeline and direct burial in the use case; the connection between the optical fibers is divided into mechanical connection and heat-shrinkable connection, and the mechanical connection is used to mechanically break the optical fiber that needs to be docked and pass the joint. The concentricity aligns the cores, which use a fusion splicer to thermally fuse the fibers to be joined together and secure and protect them by heat shrink tubing. Since the additional attenuation caused by the heat-shrinkable connection is small and has little effect on the entire network, most of the current heat-shrinkable connections are used to improve the communication capability of the network. The internal connection mode adopts two types of straight-through connection boxes: the straight-through connection connects two optical fibers of the same core number, that is, the connection of the same number of fibers when the long-distance connection is made. In the latter case, a large core number of fibers is separated from one or more small core numbers or a plurality of fibers are cross-connected. Generally, the direct connection mode is applied to the backbone network, and the differential connection mode is applied to the access layer network. The fiber optic splice box is mainly divided into the plastic shell and stainless steel shell. The general market is mainly plastic shell.