ETA Caliber 251.264

The ETA caliber 251.264 is a 27 jewels superquartz movement, part of ETA’s Thermoline family of movements. It is not a Certified Chronometer (COSC), but it can be certified and they have versions that are. This movement is an upgrade or replacement for the discontinued ETA caliber 251.262.

Variations:

There are four main versions of the caliber 251.264. They are all the same diameter, with the main differences being the dial layout and whether they are PowerDrive or PreciDrive.

• 251.264 AA – A PowerDrive and PreciDrive movement
• 251.264 AN – A PowerDrive movement
• 251.264 BE – A PowerDrive movement
• 251.264 BD – A PreciDrive movement
• 251.264 IE – A PowerDrive movement
• 251.264 HE – A PowerDrive movement

How to tell which two letter version you have? We’re still not sure. ETA only stamps them as 251.264. If you know how to tell, please let us know in the comments below and we’ll update this post.

PowerDrive and PreciDrive:

From ETA:

“The PowerDrive technology integrated into all these movements controls the motor drive and increases the speed of rotation of the hands on the dial to 200 Hz, that is to say 200 hand jumps per second. It offers the manufacturer a great deal of freedom in the display combinations. This arrangement provides one more remarkable dynamic to a modern three-counter, sport-chic look that is already well known and appreciated by the general public. The PreciDrive technology integrated into a calibre will allow the watch to achieve exceptional precision of +/- 10 seconds a year, a score equivalent to a precision of 0.027 seconds a day.”

Date Setting:

This movement sets time just like most other watches, with exception of the date. The date is mechanical. Instead of a typical quickset date where rotating the drown in position 1 flips the calendar wheel, the date is advanced by the hour hand jumping forward in one hour increments (similar to the Rolex GMT-Master II or quartz Omega Seamaster for example). This feature also assists in setting the second time zone.

Resetting the Chronograph Hand to Zero:

If your chronograph hands are not lining up after a battery change, use the following steps to reset them back to 12:00 or zero:

• For the 12 hour counter at 10:00, pull the crown out one click to hour hand/date setting position and press the top chronograph pusher. Each push will advance the hand forward one click, you can hold the pusher in to advance the hand faster. When the hand is lined up, press the crown back in.
• For the 60 minute central chrono hand, similar to the steps for the 12 hour counter above, pull the crown out to hour hand/date setting position and use the bottom chronograph pusher to advance the hand until it is lined up. Push the crown back in.
• For the 60 seconds central chronograph hand, pull the crown out 2 clicks to the time setting position. Use the top chronograph pusher to advance the hand until it is lined and push the crown in.
• To reset the 1/10 second subdial hand at 2:00, pull the crown out 2 clicks to the time setting mode and use the bottom chronograph pusher to advance the hand until it is lined up. Push the crown back in.

The small seconds subdial at 6:00 does not need reset because it is continuously running.

The caliber 251.264 shown here was found in a Breitling Chronospace Evo Night Mission. Breitling refers to this movement as the caliber 73 when they use it in their watches.

Replacement Prices:

At the time of this post, replacement prices for the 251.264 were found online for $129.95.

Macro Image Gallery:

ETA 251.264 Tech Sheets (PDF):

Additional Resources:

• More ETA watch movements