The present invention provides a vent assembly suitable for use with a respiratory mask of the type used in CPAP treatment. In the vacuum vapor-deposition apparatus, the synchronizing means equalizes the circumference velocity v1 of the coating roll and the circumference velocity v2 of the takeup guide roll. A posting by an author participating in the discussion is accepted, and a recommendation is automatically produced for the author for amending the posting to increase the likelihood of response to the posting by other individuals participating in the discussion.