US: M to Europe Size 58-59
Cross-market adult earmuffs and headbands apparel conversion mapping M specifications into 58-59.

Analyzing Size Equivalence Across Markets
US: M: Corresponds to a head circumference baseline of 57 (22.4 ) with a Standard / Regular fit type.
Europe Size 58-59: Corresponds to a head circumference baseline of 59 (23.2 ) with a Standard / Regular fit type.