This Aastra Mitel DHSG cable D0062-0011-34-00 is necessary for Aastra or Mitel phone models 6735i, 6737i, 6753i, 6755i, 6757i and 6757iCT to be able to connect the Plantronics APS-11 EHS
(electronic hookswitch) and APS-1 EHS
for remote call answer/end capability. Other Aastra phone models do not need this cable. If you are unsure if you need the DHSG cable, please feel free to call us at (800)333-0020 before ordering.