The Fiber Coexistence WDM Filter (UACC-UF-WDM-XGS) is a high-precision metal-enclosed passive component that enables the seamless coexistence of legacy GPON and next-generation XGS-PON/XG-PON services on a single fiber infrastructure. Featuring 8 COM, 8 GPON, and 8 XGS/XG-PON SC/UPC ports, it efficiently multiplexes and demultiplexes specific wavelength ranges—1290–1330/1480–1500 nm for GPON and 1260–1280/1575–1580 nm for XGS-PON—with a minimal insertion loss of 1 dB and a high return loss of 50 dB. This rack-mountable 1U filter uses ITU-T G.657.A1 single-mode fiber and provides a minimum of 25 dB isolation, ensuring interference-free signal transmission while allowing ISPs to upgrade their network capacity without replacing existing fiber lines. 1-Year Limited Warranty.