O-rings are made of nitrile rubber (NBR). provides excellent resistance to acid, gasoline, oil, UV and heat Can be used in the temperature range: -30C to +120C Metric sizes from 3 to 50mm For use in pipes, machinery, motors, hydraulics, plumbing and pneumatic machinery acid, gasoline, heat and oil resistant made of NBR , not suitable for drinking water includes the following: O-rings 20 pcs. 3 mm, thickness 1.5 mm 20 pcs. 4.5 mm, thickness 2 mm 18 pcs. 18 mm, thickness 2 mm 23 pcs. 7 mm, thickness 1.5 mm 23 pcs. 10 mm, thickness 1.5 mm 23 pcs. 13 mm, thickness 1.5 mm 14 pcs. 10 mm, thickness 2.5 mm 13 pcs. 11 mm, thickness 2.5 mm 14 pcs. 13 mm, thickness 2.5 mm 13 pcs. 14 mm, thickness 2.5 mm 14 pcs. 16 mm, thickness 2.5 mm 14 pcs. 18 mm, thickness 2.5 mm 13 pcs. 19 mm, thickness 2.5 mm 14 pcs. 21 mm, thickness 2.5 mm 13 pcs. 22 mm, thickness 2.5 mm 10 pcs. 18 mm, thickness 3.5 mm 10 pcs. 20 mm, thickness 3.5 mm 10 pcs. 22 mm, thickness 3.5 mm 10 pcs. 23.5 mm, thickness 3.5 mm 10 pcs. 25 mm, thickness 3.5 mm 10 pcs. 26.5 mm, thickness 3.5 mm 10 pcs. 28 mm, thickness 3.5 mm 10 pcs. 30 mm, thickness 3.5 mm 10 pcs. 31 mm, thickness 3.5 mm 10 pcs. 33 mm, thickness 3.5 mm 10 pcs. 34.5 mm, thickness 3.5 mm 10 pcs. 36 mm, thickness 3.5 mm 10 pcs. 38 mm, thickness 3.5 mm 10 pcs. 41 mm, thickness 3.5 mm 10 pcs. 44 mm, thickness 3.5 mm 10 pcs. 47 mm, thickness 3.5 mm 10 pcs. 50mm, thickness 3.5mm