The second button, located on the front of each speaker (when plugged into a wall outlet), is speaker-specific: On the SoundFly BT, the button sports a blue Bluetooth logo for pairing the speaker with your Bluetooth devices. Rather than flashing a light, the BT uses a pre-recorded voice that announces when the speaker is in pairing mode and when it’s successfully paired. In my testing, pairing the SoundFly BT was a straightforward process.