QSFP-DD cages and QSFP-DD connectors are purpose-built for 400 Gigabit optical modules, combining high-density design with advanced EMI shielding and thermal management. QSFP-DD doubles the density of QSFP and eight differential pairs capable of 50 Gbps each to achieve 400GbE while allowing existing QSFP modules to be plugged into the same cage. As the newest hot type of optical transceivers. OSFP (Octal Small Form-Factor Pluggable) is a newer module form factor designed for 400G and beyond. The “Q” is for “quad” — a nod to the four-channel electrical interface, with each lane running at 25 Gbps for 100GbE. QSFP-DD adapts the same basic concept as its predecessor, but doubles the electrical contact.