D-LINK DEM-CB100QXS, Cable Length-100cm, Description 1m 40G Direct Attach Copper Cable for DXS-3600-EM-4QXS, Compatible DXS-3600 Series, Connector QSFP+. The DEM-CB100QXS is a 1 meter 40GbE Direct Attach Copper (DAC) cable used with the DXS-3600-EM-4QXS module. It has QSFP+ connectors at both ends.