The Seiko 3B21-0AT0 is a watch model based on the 3B21 movement.
Parts List
| DA021AM | band - metal band |
| DA021AM-LK00 | band - link |
| DA021MMLK | band - link |
| DA021PM | band - metal band |
| DA021PM-LK00 | band - link |
| DA041AL | band - leather band |
| DA021MM | band - metal band |
| DA041AL-BK00 | clasp - clasp |
| H18H12SD00B | clasp - clasp |
| DA021AM-BK00 | clasp - clasp |
| DA021AM-BKLK-12 | clasp - parts for buckle/clasp |
| DA021AM-BKLK-6H | clasp - parts for buckle/clasp |
| DA021AM-BKPN | others - pin for buckle/clasp |
| DA021AM-BKPP | others - spring bar for buckle/clasp |
| DA021AM-EP00 | others - endpiece |
| DA021AM-LK01 | others - half adjust link |
| DA021AM-LKPN | others - pin for link |
| 81190875 | others - bracelet fixing pipe |
| 81601489 | others - bracelet fixing pin |
| S130BS | others - push pin |
| DA021MMEP | others - endpiece |