Abstract: A container for containing an experimental test animal includes a body portion. A neck extends from a first end of the container for connecting the container to a source of gaseous material. An inner surface defines an opening at a second end of the container. An insert is removably retained within the neck, and has passage for fluid communication between the source of gaseous material and the container. A retainer is mounted within the opening of the container, and includes a retainer body and a retainer neck extending from the outer edge of the retainer body. A camming member is pivotally mounted to the retainer neck and is shaped to releasably engaging an outer surface of the container. A mounting ridge is formed in an outer surface of the body portion. The mounting ridge includes a retaining surface for mounting the container with respect to the source of gaseous material.