After a stint away from the American market, due to a patent infringement case, Ultrahuman has cleared US Customs and Border Protection and is officially back for sale in the country. It’s welcome news for US customers, and Ultrahuman is one of the few smart rings that gives you access to all tracking data without requiring a subscription. Even better news is that if you are one of the first buyers, you can get it at a steep discount. Let’s start with the battery life. Ring PRO offers up to 15 days on a single charge. Pair it with the new PRO Charging Case, and that jumps to 45 days. That’s not a typo. You could go a month and a half without needing a charger. The ring is built from a titanium unibody and runs on a dual-core processor with on-chip machine learning for more accurate health insights. It can store up to 250 days of health data directly on the device, so you aren’t constantly tethered to your phone.…