I bought the darts to have extras for the Tri-strike and for a dart gun that I use as a launcher. Their availability in the market has started to decrease and I don't know if Hasbro will continue to release the refill pack. They are fun because if you apply a little pressure, you can shoot them like missiles over the forts we build when we play. They are relatively durable. Their wings may come off, but there is glue available in the market that sticks to the material from which the Nerf arrows are made and they are easily repaired.