What is the Brocade 100G-QSFP28-ER4?
The Brocade 100G-QSFP28-ER4 is a QSFP optical transceiver module, listed by the manufacturer as "Brocade Compatible 100GBase-ER4 QSFP28 Transceiver (SMF, 40km, LC, DDM)". It is part of Circular Telecom's surplus and refurbished telecom/IT equipment inventory.