Poly APP-51 Electronic Hook Switch EHS Cable for Polycom SoundPoint IP and VVX Desk Phones 38439-11

Key Features

• Electronic hook switch cable. It replaces the mechanical HL10 handset lifter with an electronic connection to the phone.
• Puts ring alerts in the headset and allows calls to be answered and ended remotely, away from the desk.
• It connects a wireless headset SYSTEM that has a desk phone base to a compatible Polycom phone. It is not a headset cable.
• It does NOT work with the Poly Voyager Focus 2. That headset has no EHS-capable base and connects by BT700 adapter or USB cable instead.
• Poly's own hook switch guide verifies the SoundPoint IP 320, 321, 330, 331, 335, 430, 450, 550, 560, 650 and 670, plus the VVX300, VVX400, VVX500, VVX600 and VVX1500.
• Headset systems verified by that same guide: Savi 700 Series, CS500 and CS500 XD Series, Voyager Legend CS, and the MDA200.
• Dealer compatibility lists are much broader than Poly's own. Treat anything outside the list above as unconfirmed and check it before ordering.
• This part supersedes the APP-50. Poly's guide carries the footnote in as many words.
• Also sold as HP part number 85Q60AA.

Key Specifications

• Part class: Electronic hook switch (EHS) cable for Polycom desk phones
• Function: Remote call answer and end, plus in-headset ring alert. Replaces the HL10 mechanical lifter
• Verified phones: SoundPoint IP 320, 321, 330, 331, 335, 430, 450, 550, 560, 650, 670; VVX300, VVX400, VVX500, VVX600, VVX1500
• Verified headset systems: Savi 700 Series; CS500 and CS500 XD Series; Voyager Legend CS; MDA200
• Not compatible: Poly Voyager Focus 2 (77Y87AA, 213726-01, 213727-01). No EHS-capable base exists on that headset
• Supersedes: APP-50
• Also listed as: HP part number 85Q60AA
• Not published: Cable length, weight, warranty and a manufacturer box-contents list are not published by Poly or HP

What it does

An electronic hook switch cable does one job: it lets a wireless headset take control of a desk phone's hook switch electronically, instead of a motorised arm physically lifting the handset out of its cradle. With the APP-51 fitted between a compatible Poly wireless headset base and a compatible Polycom desk phone, an incoming call rings in the headset itself, and the user answers and ends calls from the headset while away from the desk. Without it, a wireless headset is only useful within arm's reach of the phone, or needs the HL10 mechanical lifter that this cable replaces. Poly's own guide also records that the APP-51 supersedes the older APP-50.

Which phones

EHS cables are strictly phone-model-specific and the wrong one simply does not work, so the list matters more here than on almost any other accessory. Poly's own Electronic Hook Switch Guide names this part for the SoundPoint IP 320, 321, 330, 331, 335, 430, 450, 550, 560, 650 and 670, together with the VVX300, VVX400, VVX500, VVX600 and VVX1500 families. That list was read identically on two independent passes. Dealers publish considerably wider lists, adding the CCX Series, the Edge Series and a much broader spread of VVX models. Poly's guide predates the CCX and Edge families, so its silence is not a denial, but those extensions are unconfirmed by Poly and this page does not publish them as fact.

Which headsets

The other half of the compatibility question is the headset, and it is the half that gets assumed. This cable connects a wireless headset SYSTEM that has its own desk phone base. Poly's guide names the Savi 700 Series, the CS500 and CS500 XD Series, the Voyager Legend CS and the MDA200. It does not connect a headset directly to a phone and it is not a headset cable. One widely republished dealer claim that the APP-51 is compatible with the Savi Series only is contradicted by Poly's own guide, which includes the CS500 series. As with the phone list, dealers extend this to further Savi and Voyager models that the manufacturer's guide does not name.

Not for Focus 2

This cable has nothing to do with the Poly Voyager Focus 2, and the two are cross-sold together often enough to be worth stating plainly. The Voyager Focus 2 in all its part numbers - 77Y87AA, 213726-01 and 213727-01 - connects to a PC through the BT700 Bluetooth USB adapter or a USB cable, and to a phone over Bluetooth. It has no desk phone base, so there is no hook switch for an EHS cable to control and nothing for this cable to plug into. If the requirement is remote call control on a desk phone, the headset itself has to be one of the base-equipped systems listed above. Buying this cable alongside a Focus 2 buys a part that cannot be connected.

Two things unpublished

Two gaps are worth naming rather than filling. First, neither Poly nor HP publishes a cable length, a weight, a warranty term or a box-contents list for this part; the only contents statement located anywhere describes it as the cable alone, and that is single-source dealer prose rather than a manufacturer list. Second, HP's own title for the HP-format number 85Q60AA carries a TAA designation that the legacy 38439-11 does not, while dealers treat the two numbers as straight equivalents. Whether Trade Agreements Act compliance actually distinguishes them could not be established. For a federal or GSA buyer that is not a detail, so no TAA claim is made here against 38439-11.

Barcode Printer Shop supplies genuine Poly accessories by exact part number, with the manufacturer's own compatibility list published and the dealer extensions flagged as what they are. Contact us to learn more or secure this solution for your business today.