The Apple Watch Series 12 and Apple Watch Ultra 4 are all about what’s happening underneath. Headlined by a new Health Sensing System, they bring some of the biggest improvements to Apple Watch health tracking in years. I’ve spent the last week with the Apple Watch Series 12 and Ultra 4. Here’s everything you need to know. Buy Apple Watch Series 12 from $390 (Reg. $399) Buy Apple Watch Ultra 4 Black from $780 (Reg. $799) more…