The Seiko 8420-004B is a watch model based on the 8420 movement.
Parts List
| 205N10SN00 | crystal |
| 25M02NS4 | crown - crown |
| 0G1900N01 | case back gasket - case back gasket |
| KK06A | band - band |
| 08R12D2M | others - minute hand |
| 08R12D2H | others - hour hand |
| A120BS | others - push pin (for lb) |
| 84200060XS13 | others - dial |
| 0354815 | others - winding stem |
| 82702860 | others - case ring |
| 8420004B27 | others - case |
Caliber 8420
