https://www.gearlinkoptic.com/products/sfp-10g-tx1330-rx1270-40km-lc-transceiver/ The SFP-10G-BX40 series single mode sfp transceiver is a small form-factor pluggable module for duplex optical data communications such as 10GBASE-LR/LW defined by IEEE 802.3ae. It is with the SFP+ 20-pin connector to allow hot plug capability.