Shimano BB-ES300 Octalink bottom bracket for BSA and 68/73mm mm case width. There are various versions:
- for chaincase
- without chaincase
- with spacer (chaincase can be used by using the spacer)
- E-Type version
Among other things, suitable for:
- FC-M521
- FC-M522
- FC-M523
- FC-M4000
- FC-T4010
- FC-M3000-8
- FC-T3010-8
- FC-2403
- FC-2450
- FC-R453
Case width: 68/73mmmm
Material: axle steel