The Seiko W339-4B20 is a watch model based on the W339 movement.
Parts List
| 0Z2900N01 | case back gasket - case back gasket |
| 8060544B | pusher |
| 8060506F | pusher - (button(10h)) |
| EC0060B01 | pusher - pusher gasket |
| 8060540C | pusher - button (8h) |
| FA50EE | band - leather band |
| T180CS | others - push pin |
| 81350540 | others - button spring |
| 81400669 | others - button spring clip |
Other models with the same movement
| W339-4A08 |
| W339-4A10 |
| W339-4A20 |
| W339-4A30 |
| W339-4A40 |
| W339-4A48 |
| W339-4A50 |
| W339-4A60 |
| W339-4A68 |
| W339-4A70 |
| W339-4A90 |
| W339-4B00 |
| W339-4B10 |
| W339-4B30 |
| W339-4B40 |
| W339-4B50 |
| W339-4B60 |
| W339-4B70 |
| W339-4B80 |
| W339-4B90 |
| W339-4C00 |
| W339-4C10 |