Plantronics APP-51 EHS Cord (formerly APP-50 APP50) for Polycom Unified IP Phone models 320*, 330*, 321*, 331*, 335, 430, 450, 550, 560, 650, 670 and VVX300, VVX310, VVX400, VVX410, VVX500, VVX600, VVX1500 and Digium IP phone models D40, D45, D50, D70. Use this APP-51 electronic hookswitch adapter (EHS) instead of the HL10 handset lifter for remote call answer/end capability. Must be used with Plantronics wireless office headset systems CS500-Series and Savi models WO100, WO200, WO350, W710, W720, W730, W740 or Voyager Legend CS. The Polycom Unified IP phone models listed above support this electronic hookswitch so no HL10 handset lifter is needed. The APP51 EHS will provide a beep tone in your earpiece to alert you to a new call coming in. Simply press the button on your earpiece from anywhere within range to answer/end your call.
*IMPORTANT: *For Polycom IP 320, 321, 330 and 331 you will also need Polycom part number 2200-11095-002 as shown below to use this hookswitch adapter.