A process for controlling a level of a product in a container , the process comprising: engaging an exterior surface of the container containing the product at a first product level ; applying a force to the exterior surface of the container to cause the container to change from a first volume (V 1 ) to a second volume (V 2 ); whereupon cessation of the force results in the container containing the product at a second product level , characterized by : the first volume (V 1 ) being less than the second volume (V 2 ); engaging the exterior surface of the container containing the product at the first product level includes engaging an engagement feature on the exterior surface of the container , wherein the engagement feature is a projection on the exterior surface of the container , wherein the projection is a sprue resulting from an injection molding of a preform used to form the container , and applying the force to the exterior surface of the container to cause the container to change from the first volume (V 1 ) to the second volume (V 2 ) includes pulling the projection with a complementary end portion of an exterior rod disposed exterior to the container to cause the first volume (V 1 ) to be increased to the second volume (V 2 ). engaging an exterior surface of the container containing the product at a first product level ; applying a force to the exterior surface of the container to cause the container to change from a first volume (V 1 ) to a second volume (V 2 ); whereupon cessation of the force results in the container containing the product at a second product level , characterized by : the first volume (V 1 ) being less than the second volume (V 2 ); engaging the exterior surface of the container containing the product at the first product level includes engaging an engagement feature on the exterior surface of the container , wherein the engagement feature is a projection on the exterior surface of the container , wherein the projection is a sprue resulting from an injection molding of a preform used to form the container , and applying the force to the exterior surface of the container to cause the container to change from the first volume (V 1 ) to the second volume (V 2 ) includes pulling the projection with a complementary end portion of an exterior rod disposed exterior to the container to cause the first volume (V 1 ) to be increased to the second volume (V 2 ). the first volume (V 1 ) being less than the second volume (V 2 ); engaging the exterior surface of the container containing the product at the first product level includes engaging an engagement feature on the exterior surface of the container , wherein the engagement feature is a projection on the exterior surface of the container , wherein the projection is a sprue resulting from an injection molding of a preform used to form the container , and applying the force to the exterior surface of the container to cause the container to change from the first volume (V 1 ) to the second volume (V 2 ) includes pulling the projection with a complementary end portion of an exterior rod disposed exterior to the container to cause the first volume (V 1 ) to be increased to the second volume (V 2 ). <EOS>