The ES300 is a splined bottom bracket for use with Shimano Octalink chainsets, available in a number of shell widths and spindle lengths. The cartridge design allows easy installation without the need for adjustment.Featuring an oversized 22mm diameter hollow cold forged Cr-Mo spindle and Shimano's Octalink design, the ES300 bottom bracket is stiff, strong and lightweight giving a more efficient pedaling platform and improved power transfer compared to traditional square tapered spindles.The sealed cartridge assembly with oversized ball bearings and maintenance free high efficiency rubber seals keep out dirt, mud and water, increasing performance and lengthening service intervals.