the present invention provides an improved , leak proof , air tight , cost - effective , plastic liquid specimen container device and methods of use , comprised of a container , a lid , a lid groove containing a gasket therein that is configured to cover and tighten over the rim of the container , a lid flange , and a thin hook in the container containing a second gasket that is compressed by the lid flange when the lid is closed over the container . the improved container device of the present invention thus provides two , independent , internal seals that protect the liquid contents therein for extended periods of time , even if the plastic undergoes deformation , during transport , especially air transport , and under varying temperature and atmospheric pressure .