https://uk.insight.com/en_GB/shop/product/SFP-10G-ER40-WR/WIRE+TECHNOLOGIES+INC/SFP-10G-ER40-WR/Wire-Technologies-Cisco-SFP-10G-ER40-Compatible---SFP--transceiver-module---10GBase-ER---LC-single-mode---up-to-40-km---1310-nm/?srsltid=AfmBOoqw-kmWehzVjXFimSLdAwrzUpXpCU7JIgUWZzNC6JwnhpnEjc_8