Static window ventilator for double glazed windows 12-32mm thick. Complete with Stormguard. Performance: 7796mm2. For use with double glazing units. Aperture 162mm. All Vent-A-Matic models are designed for simple two part fitting into the glass aperture. For additional security and weather tightness, a little silicone glazing sealant can be applied to the external retaining ring. Vent-A-Matic ventilators can be cleaned with normal window cleaning materials.