The Nanit Breathing Wear Band in Grey works with the Pro Camera (sold separately) to safely and comfortably detect your babys breathing motion in almost any sleep positionwithout any sensors, electronics, or radars. Using patented computer vision technology, Nanit tracks breaths per minute (BPM) and responds quickly to changes by sending real-time alerts through the app and to the camera should your little one need you. Think of it as a gentle hand on your babys chest when you cant be cot side. Monitors babys breath so you can catch a breath.