Aluminum alloy structure design makes it lightweight while ensuring high strength, high hardness and corrosion resistance. Rubber ring design ensures excellent sealing effect, dust and water resistance. Anodizing and flower design brings bright color and good decoration effect. It is constructed of aluminum alloy material. The inner diameter is 1.98cm, the outer diameter is 2.59cm. It is suitable for bikes. Item Name: Crankset Dust Cover Material: Aluminum Alloy Features: High Strength, Good Toughness, Wear Resistant Size Details: Inner Diameter: 1.98cm/0.78" (Approx.) Outer Diameter: 2.59cm/1.02" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Crankset Dust Cover 1 x 18mm Rubber Ring 1 x 20mm Rubber Ring