903 H4 is a navigation chronograph by Sinn.
Unlike the other navigation chronographs of Sinn (Sinn 903 St), which are provided with self-winding movement, this model operates in the classic way with manual winding. Thereby via glass bottom an unobstructed view of the movement opens up, because no rotor prevents the free view.
As manual winding movement the rare 1883 by Lemania is used. The watch offers a hands date and also a moon phase indication.
- Manual winding chronograph movement Lemania 1883, 21,600 A/h
- 18 jewels
- Shock proof according to DIN 8308
- Anti-magnetic according to DIN 8309
- Stainless steel, DIN material No. 1.4435, polished/satin-finished
- Ø 41 mm, height 13.4 mm
- Top glass: high-domed sapphire crystal, with anti-glare treatment on both sides
- Caseback screwed, with sapphire crystal glass, with anti-glare treatment on the inside
- Integrated rotating bezel with logarithmic scale division, bidirectional rotating via crown at 8 o'clock
- Crowns with double O-ring seal, unverschraubbar
- Waterproof to 100 m, low pressure resistant
- Hours, minutes, small seconds with hacking seconds
- Hands date and moon phase at 12 o'clock, quick correction by two pushers at 10 o'clock
- Chronograph: hours (at 6 o'clock) and minutes (at 3 o'clock) in totalisers, central seconds, stop time max. 12 hours
- Slide rule function
- Anthracite mat galvanised dial
- Counters black glossy galvanised, hour indexes coated with special long-lasting, luminous paint, UV-resistant
- Leather strap with tang-type buckle and solid stainless steel bracelet inclusive
- 2 years