Expanded aluminum foil filter Aluminum air filters are composed of multilayer aluminum foil mesh, which has been slit and expanded. The air flow rate of filter could be adjusted through combine with different layers or different expended foil mesh, according to customer’s requirement. The frame of U style or V style could be added matching with filter size depending customer’s demand. Application These filters are commonly used in home appliance, air conditioner, and kitchen range hoods.-UL certificate, under RoHS instruction