| 12B3 - British standard pilot bore roller chain sprocket |

| Attribute | Value |
|---|---|
| Boss Dia | 53 |
| Outside Dia | 81.5 |
| Number of Teeth | 12 |
| Pitch | 3/4 |
| Overall Length | 70 |
Disclaimer: Should a manufacturer of a given part not be available then a direct equivalent from an alternative manufacturer will be supplied.