Have you seen the submarine fiber optic cable? It is a special optical cable, its performance indicators and various quality requirements are very high, and the general factory cannot produce it. Due to its particularity, it also has high requirements on the manufacturer. Products like fiber optic splitters are used on land, so they are relatively high in production. It is relatively simple, and the requirements for suppliers are not so high. Common ones are 1×4 and 1×8.