... .OEM producing GZHF is a custom-designer and made-to-specification producer of UL certified air filters. Our filters are ... appropriate: Size Customized Frame aluminum alloy stamping/extrusion or according to client's request Medium color Black, gray, green, ... class 2,ISO 9001:2008,OHSAS 18001:2007 Application Industrial,medical,telecom,electronics,networking,communications,HAVC,broadband/CATV.,etc ... ...