====== Sinn 903 H4 ======
{{wst>image_r|Sinn_903_H4|Sinn 903 H4}}
**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.


<WRAP ud ud_mod>

**Movement:**
  * [[Manual winding]] [[chronograph]] movement [[Lemania 1883]], 21,600 A/h
  * 18 [[jewels]]
  * [[Shock proof]] according to DIN 8308
  * [[Anti-magnetic]] according to DIN 8309

**Case:**
  * [[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

**Functions:**
  * 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 [[totaliser]]s, central seconds, stop time max. 12 hours
  * [[Slide rule]] function

**Dial:**
  * Anthracite mat galvanised dial
  * Counters black glossy galvanised, hour indexes coated with special long-lasting, luminous paint, UV-resistant

**Bracelet: **
  * Leather strap with [[tang-type buckle]] and solid [[stainless steel]] bracelet inclusive

**Warranty:**
  * 2 years
</WRAP>

{{tag>Watch_models Chronographs Sinn_Pilot's_Watch_models Sinn_Instrument_Chronograph_models}}