APN-91 Electronic Hookswitch

HP Poly APN-91 Electronic Hookswitch (85Q59AA) is an EHS cable for using a compatible wireless headset with an NEC desk phone. It links headset call controls with the phone, so calls can be handled without reaching for the handset.

The cable supports remote answering and ending calls. The listing names CS500 and W700 series wireless headsets as compatible families, and notes that the cable can provide call alerts when you are away from your desk. It also automates call answering, making it useful for hands-free call handling in an office.

This APN-91 is identified as Poly part 89280-11 and HP part 85Q59AA. Its purpose is specific to electronic hookswitch call control with compatible NEC phones and headsets.