From brave first take-offs to the birth of commercial air travel, Breitling’s history is inseparable from that of flight. In the 1930s, Breitling’s Huit Aviation department made its name inventing precision cockpit clocks. Two decades later, it introduced yet another novel flight instrument, this time in wearable form: the Ref. 765 AVI. That pioneering pilot’s watch provided the technical backdrop for today’s Classic AVI, a collection inspired by the rugged spirit of famed early aircraft. The Classic AVI P-51 Mustang honors one of those legends. When the aircraft was built in a mere 120 days, even its developer North American Aviation, didn’t anticipate what a powerhouse it had on its hands. The P-51’s low-drag wings and engine-cooling system—considered experimental when the single-seat fighter first took off in 1940—gave it unprecedented speed and range. The addition of a Merlin engine, expanded the plane’s performance to high altitudes, making it the best all-purpose fighter of its time. As a true pilot’s watch designed to withstand the rigors of a vintage cockpit, the Classic AVI P-51 Mustang features large, highly legible Arabic numerals on the dial and bezel. The knurled bezel on the 42mm case provides optimal grip, even in a pilot’s gloved hands. Top-stitched calfskin straps give a nod to the seams found on classic flight gear, while the stainless-steel bracelet provides an elegant alternative. Pilots and other travellers will appreciate its legibility, wear ability, and understated style. The engine of the Classic AVI is the COSC-certified Breitling Caliber 23 movement, which provides approximately 48-hours of power reserve.
Size Guide
Choosing the perfect ring size is an essential part of the Hardy Brothers experience.
Our guide below will help you find the most accurate fit, ensuring comfort, elegance, and a seamless expression of luxury.
Australian Size | Inside Circumference (mm) |
---|---|
H | 46.0 |
H ½ | 46.6 |
I | 47.2 |
I ½ | 47.9 |
J | 48.3 |
J ½ | 49.3 |
K | 49.6 |
K ½ | 50.3 |
L | 50.5 |
L ½ | 51.5 |
M | 51.8 |
M ½ | 52.5 |
N | 53.1 |
N ½ | 53.8 |
O | 54.5 |
O ½ | 54.8 |
P | 55.7 |
P ½ | 56.4 |
Q | 57.1 |
Q ½ | 57.6 |
R | 58.4 |
R ½ | 59.1 |
For the most precise fit, we invite you to visit a Hardy Brothers boutique where our specialists will personally measure your finger and ensure your chosen piece is crafted to perfection.

Hardy Brothers uses standard Australian ring sizes.
Australian Size | Inside Circumference(mm) |
M 1/2 | 55.7 |
N | 57.0 |
N 1/2 | 58.3 |
O | 59.6 |
O 1/2 | 60.9 |
P | 62.2 |
P 1/2 | 63.5 |

This timepiece sizing guide is the combined length of the two straps. To determine the length of your watch band, follow the below.
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Cut out the length chart
Cut out the length chart
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Measure your wrist
Measure your wrist
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Subtract the case size of the timepiece from your wrist measurement
Subtract the case size of the timepiece from your wrist measurement
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Be sure to print this guide at 100%
Measure this box to check accuracy


Enquire about Breitling Classic AVI Automatic Chronograph 42mm Watch A233803A1B1X1