11 1/2”’ | Automatic | Swiss Lever | Sweeping Seconds | Date |

• Date with quick setting
• Movement family:
  • Otero 800: Hand winding, no date
  • Otero 801: Hand winding, date
  • Otero 804: Hand winding, date, thinner mainspring
  • Otero 900: Automatic, no date
  • Otero 901: Automatic, date
  • Otero 904: Automatic, date, thinner mainspring
  • Otero 906: Automatic, digital display, thinner mainspring
  • Otero 907: Automatic, date, day, thinner mainspring

• Listing ID: 5066
• Manufacturer / Brand: Otero
• Caliber: 904
• Size in French Lignes: 11 1/2'''
• Size range mm largest diameter: 22 - 31 mm
• Shape: Round
• Winding: Automatic
• Hands Setting: Crown
• Seconds Hand: Sweeping seconds (central seconds)
• Escapement: Lever (Swiss, English, Glashütte)
• Date, Day, Month...: Date
• Jewels: 21
• Setting Lever Screw/Pin Position: Right
• Balance Position: Bottom (120 - 240°)
• Shock Protection: Rufa-Anti-Shock
• Beats per hour: 21,600
• Balance Type: Nickel
• Power Reserve: Unknown
• Production Period: From 1968, according to the book by Hampel: Automatic Armbanduhren aus Deutschland,... (Automatic wristwatches from Germany,...)
• Country: Germany
• Identification: Marked with Otero logo and 904 next to the balance.
• Contributor ©: Uhrforum.de member Badener (Andreas Kelz)
• External Link: https://uhrforum.de/threads/identifizierte-uhrwerke-die-weder-bei-ranfft-lorenz-noch-im-watch-wiki-zu-finden-sind.86322/page-2#post-1126605