A set of cardboard box with a roof window deposited inside, where a retaining element of a ventilation damper is located and the use of the retaining element of the ventilation damper

A packed roof window, said window comprising a ventilation passage and a ventilation flap, said ventilation passage extending from an interior side of the window to an exterior side of the window, said ventilation flap being provided on the interior side of the window and being moveable being a first position, where the ventilation passage is open, and a second position, where it covers the ventilation passage. Said roof window is contained in a cardboard box, and blocks of shock absorbing materials are arranged inside the cardboard box to protect the roof window. A pane-side ventilation flap retainer made from a paper-based material is provided on or at the ventilation flap to prevent it from unintentional movement and the pane-side ventilation flap retainer is arranged between the ventilation flap and the pane. A ventilation flap retainer, and the use of a ventilation flap retainer are also disclosed.