
Decalogue Rega
Jewish way of telling the time
The “Decalogue Rega” is the flagship and most sophisticated model of the “Decalogue” collection. It is the only wristwatch in the world which measures time in the traditional Jewish way, including small units such as heleks (1/18 minute), and regaim (singular: rega) (1/76 helek, or around 0.044 seconds). Heleks and regaim have been used by Jewish astronomers since ancient times, and along with the days and the hours they are the basis for measuring time in the Jewish lunar calendar.
The rega hand is one of the fastest in watch mechanics, making a revolution once every 7.2 seconds. Konstantin Chaykin mounted this on the back of the movement, where there is a special wheel drive. Besides this, the back of the movement is also decorated with a miniature figure of a heraldic lion, a symbol of the city of Jerusalem.

Watch features
PRODUCTION

MOVEMENT
The calibre K.01-1 PS of the “Decalogue Rega” watch was developed by Konstantin Chaykin and is equipped with a reverse time indication system with anti-clockwise hand rotation, a helek indicator on the dial and a rega indicator on the reverse side of the movement. The movement was made entirely at the Konstantin Chaykin manufactory and is made according to the standards of haute horlogerie. Components finished using classical techniques: striped andperlage; fine longitudinal and circular grindings; manual chamfering, polishing; polished screw holes, pins and jewels; spherical polishing of the axel tips; and galvanized plating of rhodium and gilding. A distinctive feature of the movement is the use of four gold ouches, and placed on the back of the movement is a miniature golden figure of a heraldic lion, the symbol of Jerusalem, and a branded regulator(a device developed by Konstantin Chaykin to fine tune the effective length of the spring).
Caliber: K.01-1 PS with hand winding by Konstantin Chaykin manufacture
Accuracy: +/-15 seconds per day
Power reserve: 48 hours when fully wound
Specification
Basic mechanism: | ETA 2824-2 (diameter 25,6 mm, height 4,6 mm) |
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Size: | Diameter 31,3 mm, height 7,85 mm |
Escapement: | Lever escapement |
Half-wave frequency: | 21 600 |
Number of stones: | 17 |
Number of parts: | 165 |
Materials: | Brass, steel |
Functions: | Display hours, minutes, moon phase |

Case
Case dimensions: Diameter 40 mm
Specification
Case: | 18k rose gold |
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Glass: | Sapphire crystal with antireflective coating |
Dial: | Blue, with the embossed text of the tablets in the ancient Aramaic version of the writing, silvered dial of the hour and minute hands |
Strap: | Exclusive of high quality leather |
Buckle: | Prong buckle in gold by Konstantin Chaykin manufacture |
Water resistance: | З АТМ (30 m) |