Under Armour 1383438410L-XL M Iso-chill Armourvent STR-BLU,L/XL

M Iso-chill Armourvent STR - Color: White / White - Size: L-XL

M Iso-chill Armourvent STR - Color: Marine OD Green / Black - Size: L-XL

M Iso-chill Armourvent STR - Color: Castlerock / Castlerock - Size: L-XL

M Iso-chill Armourvent STR - Color: Midnight Navy / Midnight Navy - Size: M-L

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.