419pcs O-Ring Assortment *O ring: NBR *Case: ABS *Stretchy, durable, *temperature holding - ... 20 degree to 80 degree 419pcs O-Ring Assortment1. Materials: NBR,also can be NR, HNBR, MVQ, ACM, FLS, ... resistant, wear resistant, chemical resistant, anti-corrosion, etc. 3. Hardness: 30~90 shore A or IRHD as your ... tolerance is ± 5 shore A, and can be ±3 shore A for special products.4. Size tolerance: exactly ...