At the moment, there are three SafeDrivePod models:
The smallest round one (version 2) and the bigger Truckpod (version 3) make use of a Bluetooth chip that can only make one connection at the same time. These pods are used most often.
The new version 4 SafeDrivePod has a new Bluetooth chip that can have more connections simultaneously.
Please note that for each extra connection, more battery power is drawn: that's why we limited the maximum number of connection to two.