What is the Finisar FCLF8521P2BTL?
The Finisar FCLF8521P2BTL is a SFP optical transceiver module, listed by the manufacturer as "1 GbE 1000BASE-T Copper SFP Transceiver, 3.3V, -40°C to 85°C, RJ-45 connector, 100m". It is part of Circular Telecom's surplus and refurbished telecom/IT equipment inventory.