We strongly advise you to get your ear impression taken from a professionally certified audiologist. Please take the following precautions:
Use of biting block is required for tighter fitment. Make sure that the impressions are extended beyond 2nd bend of ear canal (indicated as yellow, see "Print this instruction"). Make sure that the extended area (indicated as white arrow, see "Print this instruction") has at least 10mm of space. Make sure to fill the area indicated as blue (see "Print this instruction").