First use:

Switch on the remote using the On / Off button on the back of the device.
The Remote will go directly into "pairing" mode.
The Remote will then detect the nearest Phantom, (keep it close to the "Master" Phantom when it is part of a stereo pair.
If this Phantom is part of a stereo pair, the remote will control the pair.

More information :

To put the Remote in "pairing" mode, press the next and previous buttons at the same time for several seconds (a pairing icon will be visible on the central led screen)
The Remote will go into "Pairing" mode.
Phantom will automatically scan for an available nearby remote.
Once the Remote is paired to a Phantom, the LEDs indicate the volume level.
If your remote is connected to a stereo pair and one Phantom drops off your network. You may need to reset the remote to the "Master" speaker.

Select the model you want to use