It is always good to buy 2 sets of the same dart flights. When you ruin a flight you can just pull 1 flight out of your new pack. This way you extend the life of your flights by 3 times and are not playing with mix-matched flights. "Dimplex" or dimpled flights are designed to create just a little more drag to stabilize your dart if you need just that little bit more fine tuning.
3 Flights Total 1 set of 3 Standard Dart Flights