Bulls NL Robson Plus Crystal Slim Black Dart Flights. For use on most Nylon or Aluminium shafts – this new concept flight simply pushes onto your normal shaft to give you a solid professional setup. The durability of the flight is excellent. Each pack contains 3 flights. Bulls NL Robson Plus Crystal Slim Clear Dart Flights. For use on most Nylon or Aluminium shafts – this new concept flight simply pushes onto your normal shaft to give you a solid professional setup. The durability of the flight is excellent. Each pack contains 3 flights.