The size guide is defined by measuring the cranial perimeter, taking the nasion and the inion as reference points.
To select the most appropriate size for the participant, the measurement should be taken as shown in the following image.

<img src="https://cms-help-center.bitbrain.com/assets/87da712b-772a-45a2-b836-3e3712a200a2.png?width=209&amp;height=208" alt="Image Png Nov 20 2020 04 49 57 31 Pm">

Extra Small EEG cap:
<ul>
<li>36-42cm head circumference</li>
<li>14.1-16.5 inches</li>
</ul>
Small EEG cap:
<ul>
<li>42-48 cm head circumference</li>
<li>16.5-18.9 inches</li>
</ul>
Small/Medium EEG cap:
<ul>
<li>45-51 cm head circumference</li>
<li>17.7-20 inches</li>
</ul>
Medium EEG cap:
<ul>
<li>48-54 cm head circumference</li>
<li>18.8-21 inches</li>
</ul>
Large/Medium EEG cap:
<ul>
<li>51-57 cm head circumference</li>
<li>20 - 22.4 inches</li>
</ul>
Large EEG cap:
<ul>
<li>54-60 cm head circumference</li>
<li>21.3 - 23.6 inches</li>
</ul>
Extra Large cap:
<ul>
<li>60-66 cm head circumference</li>
<li>23.6-26</li>
</ul>
Contact Bitbrain for more information at&nbsp;<a title="" href="mailto:support@bitbrain.com" target="_blank" rel="noopener">support@bitbrain.com</a>.&nbsp;

Frequently Asked Questions

Head Size and Versatile EEG

Recommended head diameter for Versatile EEG