Call merging is a feature of the Plantronics Savi series, such as the Savi W740, which allows you to combine or conference two different types of calls using the same headset. This means that if you are talking to someone on Zoom, you can activate this mode and call someone on their cell phone and include them in the meeting.
Leitner wireless headsets have a nearly identical feature known as UniBase mode.

How to merge calls
- Tap the Phone Mode button on the base, this will put the Bluetooth call on standby (red light flashing) and open a line for a phone call (green light)
- Once you’ve dialed out and connected to the person you want to reach on the desk phone, press and hold down on both the Phone and the Bluetooth Mode buttons on the base
- Both mode lights will be solid green, and you’ve successfully conferenced the two calls together