20 x o-ring gasketet washers: 10 x 34 x 3 x 28mm & 10 x 26 x 3 x 20mmblack rubber oil, O rings, high quality material, oil resistance, abrasion resistance and waterproof seal.O-rings are donut-shaped rings in the industry for preventing liquid or gas from leakage or leaking in an application.Suitable for both static and dynamic sealing.Product Name: O RingMaterial: rubberColor: BlackOuter diameter: 34mm / 1.3 inch ; 26mm / 1.0 inchInner diameter: 28mm / 1.1 inch ; 20mm / 0.8 inchThickness: 3mm / 0.1 inchpackage Contents:20 x o-ring gasketet washersOnly the above package content, other products are not included.Note: Light shooting 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.