Gath Surf Convertibles are fitted with comfort strip as follows:
| Fits Head Size |
| XS-Small | 7.5mm | 9mm &,, 10.5mm | 540mm - 555mm |
| Medium | 4.5mm | 6mm | 560mm - 575mm |
| Large | 9mm | 10.5mm | 580mm - 590mm |
| X Large - XX Large | 4.5mm | 6mm &,, 7.5mm | 595mm - 610mm |
This sizing chart is a guide only, as head shapes vary.
Measurements should be taken around the head - mid forehead, just above the ears.