A B-Uhr (Beobachtungs-uhren) watch is a navigational timepiece, with the earliest designs dating back to deck watches produced in the 18th century.
The overriding characteristic is extreme legibility, with an inner ring for the hours and large minute markers and numerals. The pointer or triangle at 12 is another feature found in almost all B-Uhr designs.
Sinn has complemented the historic design in the new 856 B-Uhr Limited Edition by combining the traditional look of a B-Uhr watch with the size and features that meet today's standards.
As is customary with traditional B-Uhr watches, the hour hand of the 856 B-Uhr has been reduced and points to a separate, inner hour circle, while the dominant minute hand indicates the minutes around the circumference of the dial.
The numerals, indices, triangular main marker and the minute hand are highlighted by ivory-colored SuperLuminova. The ordering of hour hand and minute hand on the black dial follows historical specifications: during operations, minutes were the more important unit of time, and it was important to be able to read them quickly and accurately.
This watch is fully Tegimented, and has a hardness of 1,200 Vickers which is up to five times harder than standard steel.
Next, this case offers magnetic field protection of up to 80,000 A/m, among the highest for any mechanical watch. The case back is nickel free offering protection to those with allergic reactions to this metal.
The case features a copper sulphate capsule which reacts with moisture to diffuse and absorb humidity in the watch.
This watch is fitted with a Sinn Bund-style brown leather strap with tang buckle. Note that the large central section of the strap shown in the first picture above (the Bund pad) may be removed for those preferring a more traditional look as shown in the second picture.
This watch is water resistant to 200 meters.