20 pcs O-ring gasket washers: 10 pcs 8 x 4 x 2 mm & 10 pcs 16 x 12 x 2 mmThis oil seal O ring is made of rubber material, round cross-section, easy to install.Applications: automotive, electrical appliances, mechanical, industrial, construction, household and other fields.Product Name: O RingMaterial: rubberThickness: 2 mm / 0.078 inchesOuter diameter: 8mm / 0,31 inches & 16mm / 0.63 inchesInner diameter: 4mm / 0.16 inches & 12mm / 0.47 inchesColor: BlackPackage Contents:20 x O-ring gasket washersOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.