RENPHO Lynx Smart Ring Silver Size 10

• Amazon now offers the RENPHO Lynx smart ring at $168.99 (regularly $229).
• Prime members get free two-day shipping, and regular members get free shipping on orders over $35 within the contiguous U.S.
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Editor's Pick: Just wear it on your finger to monitor your sleep quality all night, tracking blood oxygen, heart rate, and stress levels. No need to remove it after washing your hands—it's fine for swimming and hiking too, with 5ATM waterproofing. The battery lasts about a week, and the charging case fits in your pocket, so you can go out for a week without hunting for an outlet.