compressed air filter Dominick Hunter K220AA AO grade:1um AA grade: 0.01um AX grade:0.01um ACS grade: 0.01um Actived carbon AR grade: 1um Dust removal AAR grade: 0.01um Dust removal Model No. K003* K009* K017* K030* K058* K145* K145* K220* K220* K330* K430* K620* material: polycotton inner frame support