The TextBuster sends a blocking signal via bluetooth to the drivers phone. That happens every time the driver enters the vehicle however the TextBuster will not interfere with any other hands free or bluetooth items in the vehicle. It prevents the driver from accessing all text, email, or internet functions while driving their vehicle and it installs in minutes. The application is also password protected preventing any unwanted removal. The TextBuster server even monitors the drivers activities and will notify the person who has installed it if it has been tampered with/disabled. And you can view the history of the routes the vehicle has taken, and how fast its been going. Plus it Also has a free tracking feature, and its compatible with Android, Iphone, and even Blackberry. They usually go for $100.00