Health-tech brand Luna has launched Luna 2.0, a smart ring that uses artificial intelligence (AI) to decode how the body, mind, and environment interact. Besides tracking sleep and stress, it also includes cycle and fertility tracking for women. Luna 2.0 uses data based on temperature and recovery to predict menstrual cycle phases. The ring’s AI assistant acts more like a coach, offering contextual suggestions on energy management, movement, and recovery. Luna 2.0 is priced at $300/£300, or $329/£329 with a surge charging case, and will be available on Amazon soon.