What is the Sandstone 280-0105-ST?
The Sandstone 280-0105-ST is a SFP optical transceiver module, listed by the manufacturer as "Cyan Compatible 1G SFP, 1000BASE-BX-U, TX1310/RX1490 nm, 10km SMF LC, DDM, C-Temp". It is part of Circular Telecom's surplus and refurbished telecom/IT equipment inventory.