a container assembly for accommodating an electronic device in a panel , includes : a retainer attached to the panel ; a cover with the electronic device attached thereto pivotably attached to the retainer , and pivotable between an open position and a closed position ; a lock for locking the cover at the closed position ; a gear damper ; a rotating shelf attached to the cover and sandwiching the electronic device with the cover , a rack formed on the rotating shelf configured for engaging with the gear damper ; and an elastic support sandwiched between the retainer and the rotating shelf for biasing the cover to the open position via restoring force of the elastic support ; wherein the gear damper depresses the restoring force of the elastic support .