Material: Fluorine Rubber Color: Black Outer Diameter: 12mm / 0.47" Inner Diameter: 5.8mm / 0.23" Cross-Section Diameter: 3.1mm / 0.12" Package Contents: 10 x Fluorine Rubber O Rings 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).