Set of 2 (purple x 1, navy blue x 1) I think it will reduce the digging into the shoulders even with a heavy water bottle. It will ease the pain of the strap when carrying a water bottle to school or kindergarten. It can also be attached to a car seat belt cover. My child also uses it on their water bottle and seat belt, and they are very happy because it doesn't hurt and is easy to attach and detach.