Door transfer grilles are used to provide a natural air circulation between neighbouring areas. Specially designed reverse V blade structure hides the back of the device while enabling air flow. Counter flanges ensure that a single grille appearance is presented on both sides of the doors. Can be implemented on walls and doors with thicknesses between 300 mms and 70 mms. Door transfer grilles frame and blades are made from aluminium and only 1st class aluminium profiles are used.