... . 4. AS568, BS, JIS, metric sizes all available. Description of Good Performance O-ring Cord PAHS Approved:1. Materials: can be NR ... , IR, EPDM, IIR, butyl, PU, E/A, ECO, CSM, VITON, FKM, FPM, etc.2. Characteristics: good physical and chemical properties o-ring ... as your request, tolerance is ± 5 shore A, and can be ±3 shore A for special products o-ring. 4. Size tolerance ...