is removed and the flexible one way air valve 130 reseals preventing air from returning in the following cases the container and lid are rigid and most likely to house cups cartridges and syringes of various sizes these are accommodated either directly into the chamber or by using various holders or inserts inside the chamber this has the advantage that larger cups cartridges and syringes can be used without risk of deforming and higher vacuums can be used they have the disadvantage of being heavier and more expensive also various holders inserts can be used to allow a range of container sizes to be used referring now to fig4 in an alternative embodiment the lid assembly 10 is comprised of a lid 20 an interior nut or affixing item 40 an exterior valve 50 an air flow opening 60 in the valve a lid retention system sometimes wire u2014 this is purely for safety in case the vacuum is lost during mixing and the lid may want to come off 80 and an o ring or gasket 90 a hole exists in the lid 20 in the space created by this hole an interior nut or affixing item 40 secures an exterior valve 50 the interior nut or affixing item 40 and the exterior valve 50 together are the valve assembly 70 the valve assembly has an airflow opening 60 through which air may be evacuated in this case the mixing vessel is in this embodiment the lid 20 sits on an o ring or gasket 90 which in turn rests upon a ridge formed toward the top.