• Electronic Hookswitch Cable APS-11
• Communicates Electronically w/ the Phone
• Eliminates the Need for a HL10 Lifter
• Replaces APS-10 Cable
• Compatible With These Plantronics Headsets: 

CS55
CS70
CS510
CS520
CS530
CS540
MDA200
On-Line Indicator Savi W710
Savi W720
Savi W730
Savi W740
Savi W745
WO100
WO101
WO200
WO201
WO300
WO350

Works With Following Siemen Phone Systems: 

Siemens:
Optipoint 410
OpenStage 40
Optipoint 420
OpenStage 60
Optipoint 500
OpenStage 80
Optipoint 600

Funwerk Deskphones
Auerswald Deskphones
Agfeo Deskphones
DeTeWe Deskphones Aastra:
6739i
6753i
6755i
6757i
6757i CT
Aastra 6771
Aastra 6773
Aastra 6775
Aastra 6773 IP
Aastra 6775 IP
Aastra 5370
Aastra 5380
Aastra 5370 IP
Aastra 5380 IP

New HP PART# HP-85Q78AA