A reusable gasket may be configured for use between first and second collapsible containers of a shelter. The gasket may have a body configured to seal at least a portion of a seam defined between the first and second collapsible containers. The gasket may include at least one magnet embedded in the body. A reusable plug configured to be disposed into a cavity defined by a collapsible container may have a body configured to be compressibly secured in the cavity. The body of the plug may be made of compressible foam.