Shimano Es51 Octalink Bottom Bracket

This is a splined bottom bracket, with an oversize 22 mm diameter hollow pipe billet spindle, that reduces weight, increases strength and rigidity, that is designed for use with Shimano Octalink chainsets.
It is available in a variety of sizes 68-121, 73-121 and 73-126mm and also with a front derailleur mount or an italian thread.