I was talking about the webcam, rather than the products. Maybe someone on here will take a look and figure it out! 
The radar boxes receive a signal from the SSR (secondary surveillance radar) transponder fitted to all large aircraft. Essentially, these are the "pings" that the aircraft send in response to being interrogated by a radar system, and what air traffic control use to keep track of the aircraft.
They contain a unique identification for that aircraft, the position and speed and all sorts of other information. More information can then be gleaned by using the aircraft's unique ID to look up what the aircraft is currently doing - flight number, airline, departure and arrival airport, etc.
You connect this box to your PC and you can see all air traffic using SSR in your area plotted on a map. 8-)
A bit like this, really :
http://www.flightradar24.com/Kevin