What is the HP JD120B?
The HP JD120B is a SFP optical transceiver module, listed by the manufacturer as "X110 100Mbps OC-3STM-1 IR-1 100Base-LX Single-mode Fiber 15km 1310nm Duplex LC Connector SFP Transceiver Module". It is part of Circular Telecom's surplus and refurbished telecom/IT equipment inventory.