The terms “invisible”, “invisible fence” and “invisible fencing” are registered and considered trademarks by the Invisible Fence Brand (Invisible Fence, Inc., USA). Electronic pet fences with a buried wire are often referred to as “invisible fences”, but Dog Guard® should not be confused with the Invisible Fence Brand. Dog Guard® is not affiliated in any way with the Invisible Fence Brand. Dog Guard® and Out of Sight Fencing® are registered trademarks of Sunward Electronics, Inc.