Europe Size 52-53 to US: M
Cross-market adult earmuffs and headbands apparel conversion mapping 52-53 specifications into M.

Analyzing Size Equivalence Across Markets
Europe Size 52-53: Corresponds to a head circumference baseline of 53 (20.9 ) with a Snug / Compact fit type.
US: M: Corresponds to a head circumference baseline of 57 (22.4 ) with a Standard / Regular fit type.