Body measurements. Fly chooses the size of a head guard according to the circumference of your head.
| Size | Head circumference (cm) |
|---|---|
| S | 50–53 |
| M | 53–57 |
| L | 57–61 |
| XL | 61–65 |
How to measure
Measure around your head, just above your eyebrows and ears.
Source: Size chart from Fly (https://flysportsuk.com/pages/size-guide), checked on 30-09-2026.