Run flat tyres will usually have "run flat", "RF", or "RFT" marked on them. If your car currently has run flat tyres then it is important you replace them with run flat tyres as your cars set up has been configured to this and in many cases you may not have a spare tyre / space saver.
If you don't currently have run flats it is also advised that you don't then replace your tyres with run flats. You can however buy products now that will give you a similar effect to allow you to keep driving after experiencing a puncture, including a foam that you inject in to your tyre, offering the same sort of solution.
If you have any doubts about whether your car is fitted with Run Flat tyres, feel free to call the Easywheels.co.uk team on 0333 9000 201, who would be happy to help.