Cal. 4S24 is a hand-winding movement central seconds. It was developed by Seiko in the early 1990s and is based on the Seiko 52 stream of movements, which had been retired in 1976. Cal. 4S24 is very similar to Cal. 4S28, which has a small seconds subdial rather than central seconds. It is also closely related to Cal. 4S15, which is an automatic movement with date.
Cal. 4S24 was rarely used but was notable as the movement in the Laurel historical reissue, catalog number LJAL601.
- Seiko Laurel LJAL600 (twisted lugs, steel and gold, cream dial)
- Seiko Laurel LJAL601 (twisted lugs, steel, white dial)
- Seiko Laurel LJAL602 (plain lugs, steel, white dial)
- Seiko Laurel LJAL603 (plain lugs, steel, black dial)
- Seiko Laurel LJAL604 (plain lugs, steel, cream dial with Roman numerals)
- 1998 Seiko Hand Winding SCVG004
- 1998 Seiko Hand Winding SCVG005
- 1998 Seiko Hand Winding SCVG007
Early Seiko 4S Movements
From the 1992 introduction of the Seiko 4S family through the early 2000s, Seiko used the 4S line as a high-end movement for diverse watches, including the SUS military, Alpinist, and Titanium diver. Most of these models were retired shortly after introduction, and the series of simple 4S movements was phased out by 2003.
| Production | Watch | Winding | Jewels | Notes | |
|---|---|---|---|---|---|
| 4S12 | 1997-1998 | SCFF | Automatic | 25 | Date Fixed 24 hour hand |
| 4S15 | 1995-2001 2006 | LHAM SCFF SCVF SCVN | Automatic | 25 | Date |
| 4S24 | 1990s | LJAL SCVG | Manual | 21 | |
| 4S25 | 1993-1998 | SCVH SCVJ | Automatic | 25 | Date |
| 4S28 | 1994-2000 | LJAK SCVG SCVM | Manual | 24 | Small seconds at 6:00 |
| 4S35 | 1992-2000 | SCVK | Automatic | 25 | Date |
| 4S71 | 1995-2003 | GCBB | Automatic | 25 |