Renpho Lynx Ring ZDNET's key takeaways The Renpho Lynx smart ring is a bare-bones wellness tracker for $170. The Renpho Lynx smart ring is a $170 smart ring that's much cheaper than its competitors. Where other smart rings have added dozens of exercises to record, the Lynx smart ring offers only 30. ZDNET's buying adviceRenpho's Lynx smart ring is a good choice as a first smart ring for those with budget constraints. Look elsewhere if you want a showstopping product, of which there are many more expensive options, including the Oura Ring 4, Galaxy Ring, and RingConn Gen 2.