ETA Caliber 251.272

Manufacturer	ETA
Caliber Number	251.272
Movement Type	Quartz (battery-powered), chronograph
Lignes	13.25”’
Diameter	30mm
Height	4.6mm
Jewels	22
Frequency	32,768 Hz
Battery Cell Number	394 (SR936SW)
Stem	401-1339, Tap 10
Hand Sizes	2mm / 1.5mm / .8mm / .2mm
Functions	Central hours; central minutes; central chronograph seconds; small running seconds at 6:00; 30 minutes counter at 10:00; 1/10 second chronograph counter at 2:00; date at 3:00 or 4:00 (depending on where the brand put the cutout on the dial)
Hacking Seconds?	Yes
Country of Manufacture	Switzerland, Swiss made
Known Models	Victorinox Swiss Army Maverick, Sector 600 Chronograph, Mondaine OCR-MICR Banker’s Chronograph, Chase Durer Bomber Command Chronograph, Philip Watch Seahorse Chronograph Diver, Certina Attack 50M Chronograph, Invicta Reserve 5677 (Please add your watch in the comments below…)

The ETA caliber 251.272 is a Swiss made quartz chronograph watch movement with 22 jewels.

Official documentation for this caliber was found dated as early as October 2007, however, there are watches that were produced as far back as 1990s with this movement. The latest updates to the technical communications were November 2012.

Replacing the Battery:

The battery in the 251.272 is a cell #394 (aka SR936SW).

There are two screws securing the battery cell strap. In the picture below, notice the right pointing arrow at the top of the strap, and the hole above that. What you want to do is gently loosen the screw, but not remove it. Using your tweezers or other tool, you can put it in the hole and swivel the strap out of the way, then pry the battery up and out of the bay. When the new battery is installed, simply swivel the strap back and tighten the screw.

Note: The bottom side of the strap is simply a fork style that slides between the movement and the screw head. This means if you loosen the bottom screw, the strap will move out of place and potentially spring into the air.

Resetting the Chronograph Hand to Zero:

If the chronograph hands on your 251.272 powered watch are not resetting back to 12:00 or zero position (this is common after a battery change), than follow the easy steps below:

1. Pull the crown out one click to date setting mode (ETA calls this position 2).
2. Press the bottom pusher to advance the 30 minutes counter.
3. Pull the crown out another click to time setting mode (ETA Calls this position 3).
4. Press the top pusher to advance the central chrono seconds hand.
5. Press the bottom pusher to advance the 1/10 second counter.
6. Push the crown back in.

With the metal cover removed:

ETA 251.272 Tech Sheets (pdf):

Additional Resources:

• More ETA calibers