Abstract: A container (40) has a body (41) having an open end (42) surrounded by an outwardly and downwardly extending flange (43). A closure (44) is adapted to be sealed to the container body (41). The closure (44) has a flange clamping portion (48) such that when the closure (44) is mounted to the body (41), the flange clamping portion (48) forms a seal with at least the outer surface of the flange (43) by exerting pressure inwardly against the flange (43). The flange clamping portion (48) can also be adapted to form a seal with the open end (42) of the body (41) and the inner surface of the container body (41) proximate its open end (42). A thread ring (10) adapted to be mounted to the open end of a container is also described. The thread ring has a retaining means comprising a continuous hook (13) that is adapted to sealingly engage the open end of the container and so provide a means for closures to be readily and sealingly attached to containers.