What are run flat tyres? Essentially an RFT is a self-supporting tyre with a very different construction to that of a conventional pneumatic tyre.
The sidewall is made of thicker rubber and has been reinforced to make it stiffer. It's this section that will bear the weight once the air pressure is gone.
The bead area is where the tyre connects to the wheel rim, it's reinforced with steel wire and is a different construction in a RFT hence a different rim is required. The bead fits between the two sides of the rim to keep air in the tyre.
The RFT needs to be fitted to a specific rim, designed for use with the tyre, though tyre sizing remains the same. You can fit an RFT in place of a standard tyre but you'll need to change the rim as well, and vice-versa.
The treaded face of the tyre that contacts the road is the same as a normal tyre. The rubber used in the treaded surface is also the same as a normal tyre - the major point of difference lies in the construction of the sidewall.
Though the tread is the most likely location for a puncture, for theatrical purposes we tested the ability of RFT's by drilling a hold in the sidewall. It's worth noting that no matter where the puncture, the RFT behaves the same.