This system incorporates a telescopic double-travel worm screw that is operated from indoors with an awning-type handle that allows adjusting the opening angle.

Used for extra ventilation in bathrooms, lofts, staircases, etc…., above all in detached maisonettes or three-high flats.

In skylight bigger than 160 x 160 cm. a double direct control is installed, by means of which with just one operating system two worm screws are operated giving greater stability and strength to the unit.