6901-2RS BMX Sealed Bearing - 24mm-12mm-6mm
$ 4.99
This is one 6901-2RS bearing. This bearing will work with many hubs. It has an OD of 24mm, and ID of 12mm and thickness is 6mm.
This is one bearing; if you need a pair, buy 2!
Be sure to measure your old bearing to ensure this will fit. The appearance of this part may vary slightly from the photo.