US: 3XL to Europe Size 8.5
Cross-market men’s glove and mitten conversion mapping 3XL specifications into 8.5.

Analyzing Glove Size Equivalence Across Markets
US: 3XL: Features a palm circumference of 28.5 (11.2 ), finger length of 10.8 , hand width of 11.6 , and overall hand length of 23.8 .
Europe Size 8.5: Features a palm circumference of 22 (8.5 ), finger length of 8.5 , hand width of 9 , and overall hand length of 19.5 .