This very rare and clean Triple-Date Moon-phase vintage 1946 Omega ref. 2471-1 have a 35mm diameter. This watch is all original and have a strong manual winding movement. 
 
*** The pictures may show the reflection of the camera lens, black spots mostly ***

Details:
 
Make: Omega
Model: Triple Date Moon Phase
Reference: 2471/1
Year: 1946 (10.9m Serial)
Material: Steel
Dimensions: 35mm
Crystal: Plastic Plexi
Movement: Manual Winding 
Bracelet/Strap: Original Omega Leather Strap
Box/Papers: No/No