The Pulse Master bulb and the Pulse Link are the master devices.
The master device can have the satellite deceives, i.e. the Pulse Satellites bulbs or the Pulse Amp adapters, added to them.
Your Android or iOS device would connect to a master device in order to control your Pulse satellite devices.
The way it works is: your smart phone connects to the master device, the master device connects to the satellite devices, the Pulse app on your iOS or Android device allows you to control the master and satellite devices seamlessly.
Once system can only have one master device.
Once master device can have up to seven satellite devices connected to it.