279pcs O-Ring Assortment 279pcs O-Ring Assortment1. Materials: NBR,also can be NR, HNBR, MVQ, ACM ... , heat resistant, wear resistant, chemical resistant, 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: exactly upon ... 1~2 weeks.13. Small order quantity is welcomed. O-Ring Assortment