Etymotic ER-4 microPro Manuel De L'utilisateur page 5

Large
The eartips that are most comfortable are the best choice, but they
should seal well in the ears for best noise isolation and sound quality.
When changing eartips
make sure the eartip fits
securely on the stem of
the earphone.
ABOUT ET YMOTIC RESEARCH SELECTING AN EARTIP
3-flange
Small
Foam Glider
correct
4
incorrect