Please take the time to measure your pet! If you dont know what size collar to order, feel free to email us and we will offer suggestions. You can use a tailor's tape and wrap it around your dogs neck. Its a good idea to add a couple inches when ordering your collar. If you dog's neck measures 15 inches, you will want to order a size that would accommodate a 17 inch neck. Another thing to keep in mind is the width of the collar. A 1 inch wide collar will more than likely be too wide for a small breed dog. May I suggest folding a piece of paper or fabric to a 1 inch width and put that around your dogs neck to get a good idea of what width you will need. You can always measure the width of your current collar as well. All my collars are custom made when you order. I will begin charging additional fees for all exchanges unless it is a fault of ours. Please take the time to measure your pet or email us for advice to avoid these fees. The additional fees will be to cover materials, labor and shipping of the new item.