VIETA VM-BS29 User Manual page 16

Short press the button of either speaker, this speaker will search
the another VM-BS29 speaker (During searching, this speaker's
button, is under orange light and blue light flash alternatively). Then
the two speaker can pair automatically. After connecting successful,
the buttons of two VM-BS29 speakers, constant in blue is the
left channel, and its button is keep flashing in blue. The other
speaker button, constant in orange is the right channel, and
its button in constant blue .
Now please turn on the Bluetooth function of your mobile/other
devices. And start to search for Bluetooth devices, the "VM-BS29"
will be found, please connect it. When connected, the left channel
speaker will prompt "Device paired" and its light indicator will in
constant blue. Then the two speakers can play the Bluetooth music
in the same time.
Disconnect the two pairing speaker, short press the button of
either two speaker. The speaker will prompt "Device disconnected"
Please Note:
(1) Using this function need 2pcs power on VM-BS29 speakers
(2) Before the TWS pairing, both two speaker did not connect to other
Bluetooth device, the two speaker's buttons all are flashing in blue
(3) If these two VM-BS29 speaker paired with a third VM-BS29 before.
You need to delete the pairing memory first otherwise these two
speaker can not pair successfully. Please long press both these two
speaker's button to delete the TWS paring memory.