RENPHO Lynx Smart Ring, Subscription-Free App, Silver, Size 8 | All Day Sleep & Activity Tracking, Includes Charging Case, 7-Day Battery Life, Size Before You Buy

Get the Perfect Fit: The RENPHO LYNX Smart Ring uses unique sizing —different from standard jewelry rings or other brands.To ensure accuracy, always purchasing and measure your size with the official RENPHO Sizing Kit before buying LYNX Smart Ring.