AUSounds AU-Stream ANC Manuel D'utilisation page 5

LISTENING COMFORT
Select the right size ear tip
Select the ear tip that provides the most comfortable fit and audio
seal. Lightly pull the ear tip to remove it from the earbuds, and install a
new suitable ear tip.
Wearing earbuds
Lightly insert the earbuds into the ear and rotate it for a comfortable
fit. There is a left side and a right side earbud as indicated by the L and
R markers on them.