A good quality bottom bracket for traditional chainsets constructed with super-accurate bearings for smooth operation and improved durability. FEATURES SHIMANO quality/performance cartridge bearing square bottom bracket Better chainline stability with chain line stabilizer 3 structures available Standard E-type chain case options Adapter material: Aluminum PRODUCT SPECIFICATIONS MODEL NO BB-UN300 SERIES TOURNEY A070 Series Remarks * w/ Crank arm fixing screws spec. only ** w/ Crank arm fixing screws spec. is available Structure_Standard ✔ Axle length/shell width mm_107_68 BC1.37 ✔ Axle length/shell width mm_LL113_73 BC1.37 ✔ Axle length/shell width mm_D-H_68 BC1.37 X * Axle length/shell width mm_117.5_68 BC1.37 X ** Axle length/shell width mm_XL118_68 BC1.37 X ** Axle length/shell width mm_XL118_73 mm ✔ Axle length/shell width mm_D-NL 122_68 BC1.37 X ** Axle length/shell width mm_D-NL 122_73 BC1.37 X * Axle length/shell width mm_D-EL 127_68 BC1.37 X * Axle length/shell width mm_LL123_68 BC1.37 ✔ Axle length/shell width mm_LL123_73 BC1.37 ✔ Axle length/shell width mm_LL113_68 BC1.37 X ** Axle length/shell width mm_MM110_68 BC1.37 X ** Spindle_Square type ✔