Cisco GLC-BX40-U-I Compatible 1000BASE-BX-U SFP Transceiver Module (SMF, 1310nm-TX/1550nm-RX, 40km, LC, DOM) compatible with Cisco Nexus 9300 Series (Switch/Module : N9K-C9396PX; Uplink Module : N9K-M12PQ ), Cisco ASR 9000 Series (Modular Line Cards A9K-MPA-1X40GE), etc.