– Simple and reliable square taper bottom bracket
– Replaces both BB-UN26 and BB-UN55
– Sealed cartridge bearings
– Cr-Mo axle
– For bicycles equipped with a chain case, select BB-UN300-K
– For E-type front derailleur compatibility, choose BB-UN300-E
– Fixing bolts not included; Shimano FC-E6000 bolts suggested