The document introduces the Quad Small Form-factor Pluggable (QSFP) interconnect system, including an overview of its components and features. It discusses the QSFP cage/heat sink assembly, EMI containment cage assemblies, ganged QSFP cages, connector, and PARALIGHT active optical cable assemblies. QSFP offers higher port density than SFP and XFP, supports up to 40Gb/s per link, and follows the SFF standard.