iQ426HEPA Advanced 4-Stage Filtration System with HEPA H14IQ Power Tools' iQ426HEPA Cyclonic Dust Extractor is equipped with a four stage filtration system, two of which being the primary cyclone followed by the six secondary cyclones. Utilizing this two stage cyclonic filtration process the cyclones pull and capture large and medium sized particles out of the airstream, keeping them from reaching the third and fourth stages (Durabond Filter and HEPA Filter). Having cyclones filtering dust and debris at the