... Assortment *O ring: NBR *Case: ABS *Stretchy, durable, *temperature holding -20 degree to 80 degree 419pcs O-Ring Assortment1. Materials: NBR,also can be ... , wear resistant, chemical resistant, anti-corrosion, etc. 3. Hardness: 30~90 shore A or IRHD as your request, tolerance is ... QA: we have strict quality control and assurance systems, have 30 QC technicians and the individual testing room. 11. We ...