Decription: Description: 1. Corrosion resistance, so the rolling bearings are suitable for operation under the harsh conditions of corrosive media. 2. The density of the rolling ball is much lighter than that of the steel, so the centrifugal force of the outer ring can be reduced by 40% when rotating, and the life is greatly extended. 3. Less affected by thermal expansion and contraction than steel. Therefore, when the clearance of the bearing is constant, the bearing can be allowed to work in an environment where the temperature difference becomes severe. 4. The modulus of elasticity is higher than that of steel, and it is not easy to deform when subjected to force, so it is beneficial to increase the working speed and achieve higher precision. Specification: Specifications: Inner diameter 24MM68/73M five-way, one sprocket wheel compatible for SHIMANO FSA , mountain / road car universal and optional Color: black, red, blue, titanium Weight: 120 grams Included: 1 x Crankshaft