Plantronics Cable 85638-01 (formerly 40287-05) is used with Plantronics EHS cords
such as Plantronics APC-42 EHS
on some Cisco IP phone models where the headset port is located too far for the EHS to reach. It is ONLY
needed if you need longer cord length for your EHS, such as if you have a Cisco expansion module sidecar.