Uniden BTHS500 Owner's Manual page 11

Music Multi-Point
The BTHS500 can connect to one mobile phone for making
and receiving calls (Handsfree Profile) and connect to a second
Bluetooth device (such as an MP3 player or laptop with Bluetooth
A2DP Profile) for streaming music.
(This enables listening to music streamed from the secondary
Bluetooth device while keeping a mobile phone connected on
standby)
IMPORTANT!
The BTHS500 cannot connect to two mobile phones at the same
time for making & receiving calls (Handsfree Profile).
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