[. . . ] Press the wheel down for middle button (function can vary by software application) 5. [. . . ] Logitech, the Logitech logo, and other Logitech marks are owned by Logitech and may be registered. Logitech assumes no responsibility for any errors that may appear in this manual. If this does not work, order an optional USB Stand from Logitech Customer Support. Si cela ne résout pas le problème, commandez un support USB facultatif auprès du service clientèle de Logitech (reportez-vous au schéma de cette section pour configurer le support USB). [. . . ] If this does not work, order an optional USB Stand from Logitech Customer Support. [. . . ]