HP Poly ATA 400 1FXS (8F3H4AA#AC3) is an analog voice adapter for connecting a telephone endpoint to a VoIP service. This regional version is identified for ANZ, EU and UK and has a single FXS voice port.
The ATA 400 series can be onboarded with Microsoft Teams SIP Gateway. When deployed with that service, supported calling functions include incoming and outgoing calls, hold and resume, call forwarding and microphone mute. It provides a way to use an analog telephone endpoint in a supported VoIP calling setup.