QSFP Double Density (DD) Interconnect System Amphenol Commercial QSFP Double Density (DD) Interconnect System is backwards mating compatible with QSFP products. The connectors utilize an electrical interface with eight lanes that support 25Gb/s NRZ modulation or 56Gb/s PAM4, providing solutions up to 400Gb/s aggregate bandwidth. The 76-position, 0.8mm-pitch connectors enable up to 14.4Tb/s aggregate bandwidth in a single switch slot. The connector and cage design is backwards compatible with QSFP28 modules, which can be inserted into a QSFP DD port and connected to four of the eight electrical channels. Amphenol Commercial QSFP DD Interconnect System is ideal for communications, industrial and instrumentation, and data applications.