The Seiko 8123-520A is a watch model based on the 8123 movement.
Parts List
| ES5W38GN00 | crystal |
| 35M82NS1 | crown - crown |
| FH2881B01 | case back gasket - case back gasket |
| 86570440 | crystal gasket - plastic gasket for crystal |
| G1085S | band - metal band |
| G1085S-LKS | band - link |
| G1085S-PB1 | clasp - parts for buckle/clasp |
| G1085S-BK1S | clasp - clasp |
| 09C54KKH | hand - hour hand |
| 8123520A61 | others - case |
| 8123530LXB1L | others - dial |
| 81239 | others - machine code |
| 84310663 | others - dial ring (lower) |
| 84310683 | others - dial ring (upper) |
| A200BS | others - push pin |
| 0354765 | others - winding stem |
| 82706380 | others - case ring |
| 0801622 | others - date dial |
| 0884967 | others - holding ring for dial |
| 10C32KKM | others - minute hand |
| 13SC04ES | others - second hand |
| 0Z0060B01 | others - crown and stem gasket |
Caliber 8123
