The Seiko 3B21-0AN0 is a watch model based on the 3B21 movement.
Parts List
| D3F7AB | band - metal band |
| DG85AW | band - leather band |
| DG86AW | band - leather band |
| D3F7AB-LK00 | band - link |
| DG86AW-BK00 | clasp - clasp |
| D3F7AB-BK00 | clasp - clasp |
| D3F7AB-BKLK-12H | clasp - parts for buckle/clasp |
| D3F7AB-BKLK-6H | clasp - parts for buckle/clasp |
| D3F7AB-BKPN | others - pin for buckle/clasp |
| D3F7AB-BKPP | others - spring bar for buckle/clasp |
| D3F7AB-EP00 | others - endpiece |
| S170BS | others - push pin |
| D3F7AB-LK01 | others - half adjust link |
| D3F7AB-LKPN | others - pin for link |