Omega 20''' LO CCR NN

movement, no: 3 502 621 manufactured in 1911.

Data: Omega 20 LO CCR NN

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  19 jewels, open face caliber, sub second.
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  Size: 20''' 44.8 mm.
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  H: = 6.78 mm.
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  N: = 18.000 A/h.
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  Power reserve:

Versions: L = Lépine, O = Omega caliber, S = Savonette, A - DDR = Quality/Grade, NN = new negative wind/setting mechanism.

Grades:

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  A: 7 jewels, flat hairspring, compensating balance.
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  B: 15 jewels, Breguet hairspring, compensating balance.
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  C: 15 - 19 jewels, regulator adjuster with screw or snail-star wheel, 7-8 collets.
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  CC: Fine C quality.
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  CCC: Very fine CC quality for 19 and 20'''
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  CCR: Extra fine CC quality for 19 and 20'''
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  CCCR: 23 jewels, 15 collets for 19 and 20''', official chronometer.
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  DDR: 23 jewels, 18 collets for 19 and 20''', official chronometer, after 1922 signed Very Best.