5 1/4 x 8”’ | Hand Wind | Swiss Lever | No Seconds

• Listing ID: 19280
• Manufacturer / Brand: Optima
• Caliber: Model No. 91
• Size in French Lignes: 5 1/4 x 8'''
• Size range mm largest diameter: 0 - 22 mm
• Shape: Form
• Winding: Manual (Crown)
• Hands Setting: Crown
• Seconds Hand: None
• Escapement: Lever (Swiss, English, Glashütte)
• Date, Day, Month...: None
• Jewels: 17
• Setting Lever Screw/Pin Position: Right
• Balance Position: Right (0 - 120°)
• Shock Protection: None
• Beats per hour: 18,000
• Balance Type: Bimetallic screw balance
• Power Reserve: Unknown
• Production Period: Unknown, probably around 1923
• Country: Switzerland
• Identification: Registered by Optima on 13.08.1923 in the Swiss Official Gazette of Commerce as model no. 91. Model No. 91 is not an official caliber designation, but was used to register the design.
• Contributor ©: Uhrforum.de member Badener (Andreas Kelz)