What is the Sandstone GLC-BX-D-20K?
The Sandstone GLC-BX-D-20K is a SFP optical transceiver module, listed by the manufacturer as "Sandstone 1G SFP, 1000Base-BX-D, TX1490/RX1310 nm, 20km DMF LC, DDM C-Temp". It is part of Circular Telecom's surplus and refurbished telecom/IT equipment inventory.