Our heavy-duty boundary flags play an important role in training your pet on a new containment system. They give you and your pet a visual reference to where the containment area ends - helping your pet to learn his "safe zone" during the early training phase. We recommend placing each flag approximately 10 feet apart to remind your pet of his "off limits" area. As you feel that your pet is progressing with his training (typically after about 2 weeks), remove every other flag. Continue to remove alternating flags every 3-4 days until all flags are removed. At this time, your pet should know his limits and your lawn will be free of training flags. Flags are re-usable, so you can always replace them if you feel your pet needs a little more training.