Specifications:Material: Fluorine RubberColor: BrownOuter Diameter: 12mm / 0.47"Inner Diameter: 10mm / 0.39"Cross-Section Diameter: 1mm / 0.04" Package Contents:50(+/-2%) x Fluorine Rubber O Rings Descriptions:1.Made of fluorine rubber which has heat, fuel, and chemical resistance.2.Prevent leaks in plumbing, machinery, hydraulic, and pneumatic repairs, etc.3.Can be used across a wide temperature range from -4 degrees F(-20 degrees C) to 482 degrees F(250 degrees C).