Norsound’s NOR400 acoustic letter plate comes acoustically tested up to 40db whilst also being fire- and smoke-tested to up to 60 minutes integrity. The NOR400 has been specifically made to rectify the problem of unwanted sound being transferred in doors where cutting a hole in the centre of the door for a letter plate is a necessity. Previously this may have caused significant damage to the soundproofing of the door set but the NOR400 aims to protect its acoustic properties. Available in Gold as well as satin and polished chrome, this high quality letter plate is the perfect solution for those wanting to not only secure a fire door but who are also concerned with keeping unwanted sound to a minimum. NOTE: Screen colour may differ from actual product colour. All technical information is given as guidance only. Please refer to our technical department for test evidence. Technical Manufacturer: Norsound Fixing: Screw fix Length: 12" Material: AluminiumColour: Polished Chrome, Satin Chrome, Gold Note: This product requires the NOR-COUSTIC mastic to fit it. You may also buy this from us here.