The 2×2 850nm Single Window Multimode FBT Coupler Splitter With Steel Tube is a high-performance optical splitting and combining device designed for multimode fiber networks operating at the 850 nm wavelength. Built using advanced Fused Biconical Taper (FBT) technology, this device ensures stable optical power distribution, low excess loss, accurate coupling ratios, and reliable bidirectional operation within short-reach multimode transmission systems.