insert plates and fixing bolts are used to fix and seal FOSC, and its installation is quite simple. The FOSC is suitable for protecting fiber cable splices in straight-through and branching applications. It can be placed in aerial, underground, wall mounting, handhole mounting and duct mounting applications. Based on an advanced formula, the plastic parts are made of injection-molded, high-strength engineering plastic PC by numerical control equipment, therefore effectively prevent products from aging caused by coldness, heat, oxygen and ultraviolet radiation. The strong housing and main components provide fire resistant, waterproof, and quakeproof while protecting splice closure during pulling, torsioning and impacting.