The present invention discloses removable air duct sealing systems for obstructing and directing airflow through portions of an air duct system. Some systems include a support plate having an opening and a flexible connector having a catch and a tail, the catch for connecting the connector to an air duct system component and the tail for passing through the opening in the support plate. Some systems include a fastener connected to the support plate, the fastener being capable of interacting with the connector in dependence upon the positioning of the fastener. In some systems, the fastener has a catch capable of being configured in a position that prevents the fastener from moving in a direction relative to the flexible connector but will allow the fastener to move in another direction. Some systems also include a gasket for restricting airflow when the gasket is pressed toward the air duct system component.