The inner cannula is placed inside the main tube, which is the outer cannula, and requires care. A locking mechanism, either by a twist or snap lock, locks it within the outer tube. Depending on its material, an inner cannula may be disposable or non-disposable. A disposable inner cannula is removed, thrown away, and replaced with a new one. A non-disposable inner cannula is removed, cleaned, and then put back into the outer cannula. It is cleaned at least once a day or as recommended.