louver
n//ˈluːvə//jalusi, spjälverk, huvventilator, jalusigaller, kylargaller, ventilationsgaller
(chiefly, _, in plural) A series of sloping overlapping slats or boards which admit air and light but exclude rain etc. [from 16th c.]
Any of a system of slits, as in the hood of an automobile, for ventilation.