The Seiko 3B21-0AE0 is a watch model based on the 3B21 movement.
Parts List
| D3A2CB | band - metal band |
| D3A2EB | band - metal band |
| D3A2CB-LK00 | band - link |
| D3A2EB-LK00 | band - link |
| D3A2EB-BK00 | clasp - clasp |
| D3A2EB-BKLK-12H | clasp - parts for buckle/clasp |
| D3A2EB-BKLK-6H | clasp - parts for buckle/clasp |
| D3A2CB-BK00 | clasp - clasp |
| D3A2CB-BKLK-12H | clasp - parts for buckle/clasp |
| D3A2CB-BKLK-6H | clasp - parts for buckle/clasp |
| D3A2CB-BKPN | others - pin for buckle/clasp |
| D3A2CB-BKPP | others - spring bar for buckle/clasp |
| D3A2CB-EP00 | others - endpiece |
| D3A2EB-BKPN | others - pin for buckle/clasp |
| D3A2EB-BKPP | others - spring bar for buckle/clasp |
| D3A2EB-EP00 | others - endpiece |
| D3A2EB-LKPN | others - pin for link |
| S150BS | others - push pin |
| D3A2CB-LKPN | others - pin for link |