The 1×2 1310 & 1490 & 1550nm Three Window Singlemode FBT Coupler Splitter With Steel Tube is a high-performance optical splitting device engineered for reliable and accurate signal distribution across all three major telecommunication windows—1310 nm (O-band), 1490 nm (E-band), and 1550 nm (C-band). Utilizing advanced Fused Biconical Taper (FBT) technology, this splitter ensures low insertion loss, high splitting precision, low polarization-dependent loss (PDL), and excellent wavelength stability over all three operating wavelengths.