Nardin Marine Chronometer 1846

Does anyone know what movement is in the above mentioned wristwatch?

The movement is the UN cal 26 which is a modified ETA 2892

Dave

http://www.ulysse-nardin.com has images of the actual movements. The accuracy of my 1846 is simply phenominal. I gain about 4-5 seconds per month...well within Marine chronometer tolerances.