What is the Sandstone QSFP-BIDI-100G-ST?
The Sandstone QSFP-BIDI-100G-ST is a QSFP optical transceiver module, listed by the manufacturer as "Cisco Compatibile 100GBASE-SR SWDM4 QSFP28 BiDi 4 x 25G NRZ 850/880/910/940nm 100m DOM Duplex LC/UPC MMF Modulo Transceiver Ottico Hot P/N:QSFP-BIDI-100G". It is part of Circular Telecom's surplus and refurbished telecom/IT equipment inventory.