***** **********Best Quality Guranteed. *****Compatibility - fit for Cisco SFP-10G-LR-X, SFP-10G-LR, DS-SFP-FC10G-LW, SFP-10G-LR-S, SFP-10G-LR-Sa*****Main Specs - 10Gb/s data rate, single-mode, duplex LC connector, 1310nm wavelength, up to10km transmission distance, DDM support*****Usage - rotat the ring latch down at 90 degree angle to unlock, then insert it to the port*****Application - used in fiber switches, routers, NIC, server or other fiber optic equipments with 10Gb SFP + ports*****30 days Free-Returned, 3 years Free Warranty and lifetime technology support, please contact us, any product quality and compatibility issues