Wagner (GB) Ltd is now offering Ducotop 35 over the frame ventilation. Supplied made-to-measure with cord or rod control, the 35mm high vent has a 15,000mm2/m capacity, which can be restricted by splitting the opening flap. Over-ventilation due to wind gusting does not present a problem due to a self-regulating flap.

The Ducotop 35 is quickly fixed to the top of the frame, through pre-drilled holes, prior to the window or door being installed, thus saving fabrication time.