Horizontal closures, also known as inline type fiber splice closures, have a flat or cylindrical shape. These closures are the most common fiber optic closure types used in aerial and underground installations. For protection against the outside plant environment and damage, splices require placement in a protective enclosure, usually called a splice closure. Splices are generally placed in a splice tray which is then placed inside a splice closure or integrated into a fiber pedestal for OSP. Fiber optic closure is a device used to connect and protect optical fibers, providing optical cables with functions such as wiring, fusion, fiber storage, and protection. 9 billion in 2025, reflecting the rising demand for network reliability.