BluetoothConnectionCallback This callback is invoked when the device receives requests for Bluetooth profile connections and contains relevant information to handle the connection process. 
BluetoothPairingCallback This callback is invoked during the Bluetooth pairing process and contains all the relevant pairing information required for pairing. 


BluetoothClassFactory Builder to instantiate a BluetoothClass
BluetoothConfigManager This class is used to control various configuration options for the Bluetooth stack. 
BluetoothConnectionManager This class is responsible for handling Bluetooth pairing and connections with a remote BluetoothDevice

It allows developers to perform the following main operations. 

BluetoothProfile Lists all the Bluetooth profiles available in the system. 
BluetoothProfileManager Allows applications to enable/disable Bluetooth profiles on the system. 
ConnectionParams This class encapsulates the information about a particular connection request with a remote Bluetooth device. 
PairingParams This class encapsulates the data for a particular pairing attempt.