The 1000BASE-BX-U 120km TX1490nm/RX1550nm Simplex LC/UPC BiDi SFP Optical Transceiver Module is a long-distance, high-performance SFP transceiver designed for Gigabit Ethernet single-fiber bidirectional communication. Operating at 1490 nm for transmission (TX) and 1550 nm for reception (RX), this module enables full-duplex data transmission over a single strand of singlemode fiber (SMF) for distances up to 120 kilometers.