The 903 Classic and 903 H4 models from German watch brand SINN are navigation chronographs equipped with the rare Lemania 1883 hand-wound movement. Together with their perfect readability, clear arrangement of functions and ease of use, they also possess characteristics that users of a watch with a slide rule function need to carry out mathematical calculations.
Both 903 Classic and 903 H4 models from the SINN 903 series are practical instruments with which practically anything can be calculated – and which permit their wearers to show off their expertise and style.
While they are identical with regard to suitability for everyday use, durability and state-of-the-art technological features, they differ in appearance due to the various colors of the minute and hour counters, the little second counter and the bezel.
• 903 H4: Charcoal grey electroplated dial, Mechanical hand-wound Lemania 1883 movement, date hand and moon phase at 12 o’clock
• 903 Classic: Limited to 300 pieces. Black electroplated dial, Mechanical hand-wounded Lemania 1883 movement, date hand and moon phase at 12 o’clock.
• Lemania 1883
• Hand-wound movement
• 17 bearing jewels
• 21,600 semi-oscillations per hour
• Shock resistant as per DIN ISO 1413
• Anti-magnetic as per DIN 8309
• Case made of stainless steel, polished / satinized
• Sapphire crystal glass in front, anti-reflective on both sides
• Transparent case back made of sapphire crystal glass, anti-reflective on the interior
• Case back screw-fastened
• Meet the technical requirements for waterproofness, as set out in standard DIN 8310
• Pressure-resistant up to 10 bar
• Low pressure resistant
• Hours, minutes, subsidiary seconds
• Hand date
• Moon phase display
• Interior rotating bezel with logarithmic scale (slide-rule function)
Dimensions and Weight
• Case diameter: 41 mm
• Band lug width: 22 mm
• Case thickness: 13,2 mm
• Weight without strap: 73 gramme
Dial and Hands
Black electroplated dial (903 Classic)/ Charcoal grey electroplated dial (903 H4)
Indices coated with luminescent colour
Hour and minute hand coated with luminescent colour
Interior bezel with logarithmic scale and slide rule function
• 2 years