Cal. 8L34 is a rare hand-winding pocket watch movement used only in the 2000 Seiko Historical Collection limited edition watch. It is derived from the Grand Seiko Cal. 9S54 but has small seconds in the “lépine” location, opposite the winding crown. It is highly unusual for a pocket watch movement, running at 28,800 A/h and quite small at 12.5 ligne (28.40 mm) in diameter. Cal. 8L34 was constructed at Seiko’s Shizukuichi Watch Studio along with Grand Seiko movements.
| Production | Application | Winding | Jewels | Notes | |
|---|---|---|---|---|---|
| 8L21 | 2003-2007 | Brightz SAGL | Automatic | 24 | Similar to 9S51 |
| 8L34 | 2000 | Railway pocket watch | Manual | 20 | Small seconds |
| 8L35 | 2000-present | Brightz SAGQ Prospex SBDX Prospex SLA | Automatic | 26 | Date, similar to 9S55 |
| 8L36 | 2011-present | Credor GCBZ Galante SBLM | Automatic | 27 | GMT, similar to 9S56 |
| 8L38 | 2010-2015 | Galante SBLL | Automatic | 26 | Open Heart |
| 8L75 | -2005 | Credor GCBR | Automatic | 26 | Date, similar to 9S55 |
| 9S51 | 1998-2009 | GS SBGR | Automatic | 24 | No date |
| 9S54 | 2001-2010 | GS SBGW | Manual | 20 | No date |
| 9S55 | 1998-2010 | GS SBGR | Automatic | 26 | Date |
| 9S56 | 2002-2010 | GS SBGM | Automatic | 27 | GMT, no date |