The Seiko 4N21-5450 is a watch model based on the 4N21 movement.
Parts List
| SA3A01SN02 | crystal - crystal |
| 35MX7NS1 | crown - crown |
| 35MX7NG1 | crown - crown |
| 0F190BA1S | case back gasket - case back gasket |
| D176AZ-LK2 | band - link |
| D176HZ-LK4 | band - link |
| D176AZ | band - band |
| D176HZ | band - band |
| D176AZ-BKK | clasp - buckle |
| D176AZ-PB1 | clasp - parts for buckle |
| D176HZ-PB1 | clasp - parts for buckle/clasp |
| D176HZ-BKM | clasp - clasp |
| 1BA035A7BNS | others - hour hand |
| 3BA075F1BNS | others - second hand |
| 2BA075A5BNS | others - minute hand |
| 81180189 | others - bracelet fixing pipe |
| 4N21545061A | others - case |
| 82839590 | others - case ring |
| 81612209 | others - bracelet fixing pin |
| 4N215450 | others - case back |
| 4N215450WEA | others - case |
| 4N212620XA13 | others - dial |
| 4N212620XA23 | others - dial |
| 4N212620XA33 | others - dial |
| 4N212620XB13 | others - dial |
| 4N212620XG13 | others - dial |
| 4N212620XZ13 | others - dial |
| 4N2165 | others - machine code |
| D176AZ-BKPP | others - spring bar for buckle/clasp |
| 0351155 | others - winding stem |
| DZ0040B01 | others - crown and stem gasket |