You can create and save up to 20 unique fences in your Halo App, and they can be created anywhere in the world. If you intend to go to a zero-coverage area, you can set up your Halo Fences before you leave, and it will work seamlessly. You can edit any fence, at any time (just be sure to practice this new boundary with your dog!). Each fence needs to include a minimum of 250 square feet for your dog to roam safely, and can accommodate a maximum of tens of square miles.