SHIMANO - Bottom Bracket - Threaded - HOLLOWTECH II - 68/73 mm shell widthWith better sealing and rotation the SHIMANO DEORE bottom bracket delivers high driving efficiency.PRODUCT SPECIFICATIONSMODEL NO: BB-MT501SERIES: SHIMANO ALIVIO T4000 SeriesHOLLOWTECH II bottom bracket_Threaded bottom bracket type: Threaded bottom bracket shell width (mm)_68: Threaded bottom bracket shell width (mm)_73: