How To Set A Fixed Width Size In A Module Position

Hello, as here www.joomlack.fr/en/joomla-extensions/accordeonmenu-ck?tp=1

I wonder how is possible to limit the width size of your module when it is placed im a module position like in the center of a web page.

Thank you.

hi
just by adding a
<div style="width: 260px; float: left; margin-right: 10px;">load the module</div>
in the article html
ced