What is the Sandstone QFFP100-L4D-OELS-10K-ST?
The Sandstone QFFP100-L4D-OELS-10K-ST is a QSFP optical transceiver module, listed by the manufacturer as "MSA Compatible 100G QSFP28, 100GBASE-LR 4/D 1210 nm, 10km SMF LC, DDM, C-Temp, Sinlger Rate Version, Blue Latch". It is part of Circular Telecom's surplus and refurbished telecom/IT equipment inventory.