10 1/2”’ | Hand Wind | Swiss Lever | Direct Sweeping Seconds |

Remarks:

• The Ultra 904 has some visual similarities with the French Parrenin 90, but is not identical to it

• Listing ID: 2789
• Manufacturer / Brand: Ultra
• Caliber: 904
• Size in French Lignes: 10 1/2'''
• Size range mm largest diameter: 22 - 31 mm
• Shape: Round
• Winding: Manual (Crown)
• Hands Setting: Crown
• Seconds Hand: Sweeping seconds (central seconds)
• Escapement: Lever (Swiss, English, Glashütte)
• Date, Day, Month...: None
• Jewels: 17
• Setting Lever Screw/Pin Position: Left
• Balance Position: Bottom (120 - 240°)
• Shock Protection: Incabloc
• Beats per hour: 18,000
• Balance Type: Mono-/Bimetallic screw balance with Breguet hairspring | Glucydur | Nickel | Brass
• Power Reserve: Unknown
• Production Period: Unknown, probably around 1955
• Identification: Ratchet wheel marked with ULTRA 904. Original data sheet available.
• External Link: https://uhrforum.de/threads/identifizierte-uhrwerke-die-weder-bei-ranfft-lorenz-noch-im-watch-wiki-zu-finden-sind.86322/page-33#post-4138736
• Country: France
• Contributor ©: Uhrforum.de member Badener (Andreas Kelz)