The filter enclosed in a galvanized frame is fabricated by sheets of aluminium wire or galvanized metal. The particular pre-filters have applications in aggressive atmosphere with high velocity air streams in the ducts which results high flow rate. The aluminium filtercels are appropriate for the retrain of oil particulates in the atmosphere of an environment where sparks may be generated. An environment with similar characteristics is the kitchen of a restaurant. The aluminium filtercels are mainly distributed in standard dimensions in order to be attached to the relative air ducts.