What is the Sandstone QSFP-4SFP25G-CU3M-ST?
The Sandstone QSFP-4SFP25G-CU3M-ST is a QSFP optical transceiver module, listed by the manufacturer as "Cisco Compatible 100G QSFP28, 100GBASE-DAC, 3m 28AWG Breakout 4 x SFP28 25G, NO DDM, C-Temp, BLACK Latch". It is part of Circular Telecom's surplus and refurbished telecom/IT equipment inventory.