ATP Watches of the British Armed Forces
From Chronopedia
ATP
The Army Trade Pattern (ATP) wristwatch was a general service timepiece supplied by 18 Swiss makers in accordance with a specification requiring:
- 10½– 12 ligne, 15 jewel lever movements timed ± 30 sec. per day in 4 positions;
- metal dials, luminised, offset seconds
- stainless steel or nickel chrome waterproof cases.
Approximately 133,600 ATP wristwatches were supplied to the War Office