1. Duration of validity This has been extended to 14 November 2007. 2. Changes 2.1 Use as over flow damper According to a new DIBt (German Institute for Building Technology) regulation, the approval of the authority is required for usage when ventilation ducts are not present on both sides (over flow damper). Warning! This change will be introduced successively by the DIBt in extensions, changes or additions to building approvals for all fire dampers on the market. An ex officio change (simultaneous change to all approvals affected) is not planned at the moment. 2.2 Connection of flammable ventilation ducts The connection of flammable ventilation ducts is permissible with immediate effect. 2.3 Scope of the approval This is much smaller than in older approvals. For example, there are no longer any parts lists or drawings of individual parts. This makes the approval more friendly towards the applicant and easier to keep track of. 2.4 Regulations for use and maintenance Detailed specifications on inspection and maintenance activities are no longer part of the approval. 3. Further information For further information see the general building approval Z-41.3-321 (german version).