Due to the growing network demands, there is a wide range of models and configurations of vertical fiber optic splice closures. High-capacity versions and variations in the number of splicing trays are also available in the market to meet the complex needs of today's fiber-optic. Types of Splice Closures: Key Differences and Use Cases Fiber optic splice closures are categorized by design, installation method, and environmental resilience. Advantages: Horizontal splice closures are commonly used for applications such as trunk lines and. This guide covers the three common types, how to size by fiber count, and the install checks crews skip on bad days. The most common outside-plant shape — a cylindrical dome that mounts vertically on a strand or pole.