Cal. 681 is a simple automatic movement from Zenith. It is closely related to Cal. 680 and the rest of the Zenith Elite family. It is no longer in production as of 2020.
Cal. 681 is listed in the 2010 Zenith catalog as a new movement: “This classically handsome model features a new ultra-thin 40 mm-diameter case housing the ideally suited extra-slim (3.81 mm) elite 681 automatic caliber, beating at 28,800 vibrations per hour (4 Hz) and ensuring a 50-hour power reserve.” Note that Zenith’s website later specified the height of Cal. 681 as 3.47 mm. Given that this would be thicker than much more complicated movements, we are sticking with 3.47 mm.
Technical Aspects of the Zenith Elite Movement
The basic Elite movement measures 11.5 ligne (25.60 mm) diameter and most models are under 4 mm thick, despite a central automatic winding rotor and date complication. A few models used a larger main plate to move the date window outward or to support complications like a running 24 hour ring. The thinnest Elite movement is the hand-winding Cal. 650 at 2.83 mm and the thickest and most complicated is the large Cal. 687 at 6.20 mm.
Unusually, many Elite movements (apart from the 660 and 670 lines) feature small seconds at 9:00, a distinctive feature that differentiates the watches that use it. Some, however, feature central seconds, an adjustable 24 hour hand, a power reserve indicator, and other complications.
All Elite movements use an annular Glucydur balance wheel with a self-compensating balance spring and fine micrometer screw for adjustment. The automatic winding rotor is mounted on ball bearings like the ETA 2892 and originally included a tungsten carbide element for higher winding power. Most Elite movements boast 50 to 55 hours power reserve and all operate at 28,800 A/h.
Zenith Elite 680 and 690: Small Seconds
Cal. 680 was one of the original Elite movements introduced in 1994 and remains in production today. Most of its descendants feature small seconds at 9:00, though Cal. 690 lacks running seconds and the rare Cal. 689 relocates the subdial to 6:00.
| Movement | Years | Winding | Jewels | Seconds | Complications |
|---|---|---|---|---|---|
| Elite 680 | 1994-present | Automatic | 26 | 9:00 | Date |
| Elite 681 | 2010 | Automatic | 27 | 9:00 | None |
| Elite 682 | 1996-2014 | Automatic | 26 | 9:00 | Date, 24 Hour Hand |
| Elite 683 | 2003-2010 | Automatic | 36 | 9:00 | Date, Power Reserve at 3:00, 24 Hour Hand |
| Elite 684 | 2000s | Automatic | 26 | 9:00 | Date at 6:00 |
| Elite 685 | 2002-2015 | Automatic | 38 | 9:00 | Date, Power Reserve |
| Elite 6850 | 2008-2010 | Automatic | 38 | 9:00 | Date, Power Reserve |
| Elite 687 | 2008-2010 | Automatic | 41 | 9:00 | Date, Power Reserve, rotating 24 hour ring |
| Elite 689 | 2008 | Automatic | 31 | 6:00 | None |
| Elite 690 | Automatic | 37 | None | Moon Phase at 6:00 | |
| Elite 691 | 2010-2016 | Automatic | 27 | 9:00 | Moon Phase at 6:00, Big Date at 1:30 |
| Elite 692 | 2009-present | Automatic | 27 | 9:00 | Moon Phase at 6:00 |
| Elite 693 | 2012-2017 | Automatic | 26 | 9:00 | 24 Hour Hand |
| Elite 68 | 2006-2010 | Automatic | 27 | 9:00 | Central Power Reserve |