... all available. Description of Excellent Aluminum O-ring for Ozone-proof:1. Materials: can be NR aluminum o-ring, HNBR, Buna, ... FDA, NSF, KTW, WRAS, LFGB, etc. 8. Applications: automobile aluminum o-ring, electrical appliance, mechanical, industrial, construction, household, medical and ... other fields. 9. QC/QA: we have strict quality control and assurance systems, have 30 QC technicians and the ...