Narrow Ring 15# inside Circumference 55MM, Ring, Surface Width 7MM, Adjustable Range Approximately 10#-17# Wide Band Ring 15# inside Circumference 55MM, Ring, Surface Width 10MM, Adjustable Range Approximately 11#-17# Narrow Ring 20# inside Circumference 60MM, Ring, Surface Width 7MM, Adjustable Range Approximately 15#-25# Wide Band Ring 20# inside Circumference 60MM, Ring, Surface Width 10MM, Adjustable Range Approximately 16#-25#