How do I pair my Discovery 600 Series headset to my cell phone or other device?
To pair your Discovery 610/640/640e/645/650/650e/655/665 with your phone or other device:
Turn on your device’s Bluetooth feature.
Start with the headset powered off. Press and hold the power button for about 5-6 seconds until the light on the headset starts flashing an alternating red-blue. Release the power button and set the headset aside.
On your cell phone, go to the Bluetooth menu and search for (or add) a device. The cell phone should find the headset. The headset will appear as "6xxPlantronics" in your list of devices.
If prompted for a passkey, enter 0000 (four zeros). Note: Do not be alarmed if your phone does not prompt you for a passkey, because many phones do not.