Eastern mid bottom bracketthis mid bottom bracket will only work in bikes that have either mid or american bottom brackets these bearings come ready to install in american bb frames but can easily convert to fit mid bb frames you just need to remove the bearing from the outer shell they include all spacers and chainwheel adaptors features mid bb precision sealed bearings 41mm od spacers and chainwheel adaptors included internal diameter 19mm weight 11 7oz with cupsbuy eastern compon