Under Armour 1383438-418-S/M M Iso-chill Armourvent STR

M Iso-chill Armourvent STR Blue Smoke/Black M/L

M Iso-chill Armourvent STR Blue Smoke/Black XL/2X

M Iso-chill Armourvent STR / Blue Smoke / / Black / L/XL

M Iso-chill Armourvent STR -Silica Green / / Hydro Green -S/M

This hat was designed to keep your head cool by dumping excess heat through special vents that allow hot air out, but are small enough that the sun's rays aren't an issue.