Made of high quality material, and practical to use Road Bike CrankArm Bolt Kit Self-Extracting 30mm for ROTOR Bicycle Crank Screw The inner screw is suitable for ROTOR road crankset and 30MM axle, and the outer cover can be used for 24MM and 30MM axle. When using our internal screws, please replace all the gaskets of the crank. The thicker gaskets attached to the screws are used where the screws are in touch with the outer cover, and the thinner ones are used where the screws are in touch with the crank. The inner screws are divided into left and right, the driving side is the right side, the screws have the letters RIGHT on them, and the left side is the non-driving side. There are letters LETF on the screws, please pay attention to distinguish them. Color: Black Material: Metal Specifications:Left/Right Package Contents: 1 x Screw Only the above package content, other products are not included. Note: Light reflection 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.