The Seiko 3B21-0AP0 is a watch model based on the 3B21 movement.
Parts List
| D3G1JE | band - metal band |
| D3G1JE-LK00 | band - link |
| D3G1LE | band - metal band |
| D3G1LE-LK00 | band - link |
| D3G1LE-BK00 | clasp - clasp |
| D3G1JE-BK00 | clasp - clasp |
| D3G1JE-BKPN | others - pin for buckle/clasp |
| D3G1JE-BKPP | others - spring bar for buckle/clasp |
| D3G1JE-LKPN | others - pin for link |
| 81190075 | others - bracelet fixing pipe |
| 81610309 | others - bracelet fixing pin |
| D3G1LE-BKPN | others - pin for buckle/clasp |
| D3G1LE-BKPP | others - spring bar for buckle/clasp |
| D3G1LE-LKPN | others - pin for link |