... 20 degree to 80 degree 419pcs O-Ring Assortment1. Materials: NBR,also can be NR, HNBR, MVQ, ACM, FLS, CR ... , SBR, SI, BR, IR, EPDM, IIR, PU,E/A, ECO, CSM, VITON, FKM, FPM, etc.2. Characteristics: oil ... anti-corrosion, etc. 3. Hardness: 30~90 shore A or IRHD as your request, tolerance is ± 5 shore ... A, and can be ±3 shore A for special products.4. Size tolerance: ...