What is the Sandstone SFP-25G-BX-D-40K-I-ST?
The Sandstone SFP-25G-BX-D-40K-I-ST is a SFP optical transceiver module, listed by the manufacturer as "Cisco Compatible 25G SFP28, 25GBASE-BX-D, TX1330/RX1270 nm, 40km SMF LC, DDM, I-Temp $400". It is part of Circular Telecom's surplus and refurbished telecom/IT equipment inventory.