There are many types of flight protectors out there, but, Trident 180's are unique in that they are the first to offer the protection built into the "incoming" dart.
99% of all darts have a "lip" on the barrel where the point meets the barrel. On all collisions except the "Robin Hood" shot, it is this lip that does the damage to the flight. Trident 180's fit over the point of the dart and then slide up to the barrel and cover the lip. This leaves a perfectly smooth graduation curve that allows the incoming dart to gently brush aside the obstructive flight without damaging it. Trident 180's offer a huge increase in the life of your flights.
Card holds four sets. That's enough for 12 darts.