Most bracelets are closed, rigid.

The size described in the product sheets indicates the diameter of the bracelet, in mm.
To approximately determine your rigid bracelet size, you need to measure the size of your palm to ensure it fits through the bracelet's diameter at its widest point, as shown in the image below. Add 0.3 mm or 0.4 mm.
Refer to the conversion table below to determine the minimum size of your bracelet. You can select one or two sizes up depending on your preference.
| Your palm size (cm) | Minimum bracelet diameter |
| 6.0 to 6.5 cm | 50 to 52 mm |
| 6.5 to 6.9 cm | 52 to 54 mm |
| 6.9 to 7.3 cm | 54 to 56 mm |
| 7.3 to 7.7 cm | 56 to 58 mm |
| 7.7 to 8.1 cm | 58 to 60 mm |
| 8.1 to 8.3 cm | 60 to 62 mm |
| 8.4 to 8.6 cm | 62 to 64 mm |
| 8.6 to 8.8 cm | 64 to 66 mm |
| 8.8 to 9.0 cm | 68 to 70 mm |