![Longines 503-227, Fourth wheel](http://urdelar.se/cdn/shop/products/0000_longines_4_2_4908e4e7-db94-4718-ba60-503a347831d3_{width}x.jpg?v=1609711617)
Longines 503-227, Fourth wheel
- LONGINES original part in factory sealed packaging.
- Fits cal: 503, 505, 506, 507, 508
Versions: 19800 A/h:
- 501: date.
- 503: day, date.
- 505: quickset date.
- 507: day, quickset date.
Versions: 21600 A/h, micrometer regulator:
- 506: quickset date.
- 508: day, quickset date.