Module for the temporary opening of the ventilation version. Often it is not necessary for an electromotive drive to open a ventilation unit (window or skylight) over its entire stroke. It is sometimes enough "just a small gap" for ventilation. With this module, the stroke of a drive can be timed limit. When the "EMERGENCY OPEN" function is triggered, the module has no influence and the drive opens beyond the maximum stroke. WSA 304C for WSC 308 01