Material: Fluorine Rubber Color: Black Outer Diameter: 7mm / 0.28" Inner Diameter: 5mm / 0.2" Cross-Section Diameter: 1mm / 0.04" Package Contents: 25 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).