Match the retail size number
Disposable hearing aid cells are usually zinc-air. Packs are labelled 10, 312, 13 or 675 with a colour tab (yellow, brown, orange, blue).
Use the number on your empty pack or the tray marking — sizes and chemistries are not interchangeable even when diameters look similar.
OEM charts from brands such as Phonak (non-rechargeable model → size with IEC PR70 / PR41 / PR48 / PR44) and Widex (colour legend) use the same four retail sizes — still match your empty pack or manufacturer table, not a guess from brand alone.
Activate zinc-air correctly
Peel the tab only when you are ready to use the cell. Wait about a minute for air to activate the chemistry, then insert.
Removing tabs early wastes capacity.
Rechargeable hearing-aid systems
Many modern hearing aids charge in a case and have no zinc-air tray. They are not compatible with ZA10 / ZA312 / ZA13 / ZA675 disposable packs.
Do not force a disposable cell into a sealed rechargeable aid or its charger case.
Safety
Hearing aids are medical devices — follow your audiologist and the manufacturer. This chart is a size reference, not a clinical fitting.
Keep button and zinc-air cells away from children and pets.