Plantronics APU-7 EHS has been discontinued. If you have one of the older, discontinued Plantronics wireless headsets such as CS55, CS50, CS70N, CS351N, CS361N, you will unfortunately not be able to use the newer EHS cords. Your options would be to get the older model HL10 handset lifter with right angle plug (60961-34), or buy yourself a brand new wireless headset like the CS540
with the new EHS APU-72
Use this APU-7 electronic hookswitch adapter (EHS) instead of the HL10 handset lifter in order to answer and end your calls from the headset from anywhere in your 300 ft. range. The Plantronics APU7 eliminates the need for mechanical lifting of the handset receiver since the hookswitch capability is provided electronically by the specific Nortel, Avaya and Cisco telephone models listed above.