The phone features a convenient Redial function for quickly calling the last dialed number, while the Mute function allows private conversations without the caller hearing background discussions. It also supports switchable Tone/Pulse dialing modes, ensuring compatibility with a variety of telephone systems.

With its wall-mountable design, the HA399(100)T can be installed on a wall or placed on a desk, making it a practical solution for homes, offices, reception areas, and workspaces.