100G QSFP28 to 4x 25G SFP28 PCC (Passive Copper Cable), also known as Direct Attach Copper (DAC) cable or Twinax cable, provides robust connections between 100G Ethernet and 25G Ethernet systems. Each cable consists of four lanes each operating at data rates of up to 25Gb/s. The passive copper cables require no additional power to ensure quality connectivity. The cables are compliant with SFF-8402 SFP28 and SFF-8665 QSFP28 standard specifications and provide connectivity between system units with a QSFP28 port on one side and up to four different SFP28 ports on the other.