Schubert SR1 Manual De Instrucciones página 15

Tip:
To ensure the helmet is as quiet as possible, the fit on the
underside of the helmet is important. This area needs to be
well sealed off. If you have a slim neck, it is advisable to use a
scarf additionally.
aeroacousitcally non-critical area aeroacoustically critical area
aeroacousitcally non-critical area
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