Pleat Filter to Suit SMH2500 Negative Pressure Unit. Panel filters are pleated filters which are assembled with a wire frame. Panel air filters are pleated filters which are assembled within a moisture-resistant cardboard frame. SPECIFICATIONS Pleat filter to suit SMH2500 negative pressure unit. Size: 445x445x94 Firm cardboard frame Filterclass according to EN 779:2012: G4 Maximum final...