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 |

Cut out the length chart
Measure your wrist
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 Speake Marin Openworked Tourbillon Black DLC 42MM
Details
| Vendor | Speake Marin |
| Metal | Black DLC |
Read more information regarding our Product Disclaimers.
Product Details
The new SMA05 Calibre is part of the SMA proprietary movement collection and positions a strong element at 1:30: the flying tourbillon. Speake-Marin is the only watchmaker who positions its tourbillon there.

























