Fiber Optic Splice Closure  is a connecting part that connects two or more optical cables together and has protective components. It must be used in the construction of optical cable lines, and it is one of the most important equipment. The quality of optical cable joint boxes directly affects The quality of the cable line and the service life of the cable line. So what are the internal structures of the Fiber Optic Splice Closure? 1. Support frame: It is the main body of internal components. 2. Optical cable fixing device: used for fixing the optical cable and the base and fixing the optical cable reinforcing component. The first is the fixing of the cable reinforcing core inside; the second is the fixing of the cable and the support frame; the third is that the cable and the connector box are sealed and fixed by the heat shrinkable sheath. 3. Fiber-optic placement device: The fiber-optic connector and the remaining fiber can be stored in sequence. The length of the remaining fiber should be no less than 1 meter, and the remaining fiber-optic disk should have a mean diameter of not less than 35 mm. The storage tray can be four layers, the capacity is large, and the storage tray can be adjusted according to the number of cores connected by the optical cable. 4. Optical fiber joint protection: The heat-shrinkable protective sleeve can be placed on the core fixing clip in the receiving tray. 5. Sealing the optical cable and the joint box: sand the junction of the joint box and the optical cable with the abrasive cloth on the cable and the base table, wipe the sanding place with the cleaning agent, attach the aluminum foil, and place the heat-shrinkable tube in the joint box. At the entrance of the cable, the burner is slowly heated according to the middle and rear ends, so that the entire heat-shrinkable tube can be completely shrunk.