The invention relates to an adjustment device for adjusting shutoff strips of an at least partly closable air inlet of a motor compartment of a motor vehicle between at least a first position in which the shutoff strips leave the air inlet at least partly open and a second position in which the shutoff strips at least partly close the air inlet. The adjustment device comprises a drive unit, situated in a housing, which has a motor and a drive train with reduction stage. The drive train comprises an output shaft provided with a first coupling means facing outside the housing and a second coupling means facing outside the housing, opposite with respect to the first coupling means. The coupling means are configured to cooperate with, respectively, a first and a second coupling element of a first and second set of shutoff strips, respectively, for coupling the output shaft on both sides of the housing to the respective set of shutoff strips.