Abstract: The invention relates to a lid (1) and a method of opening the lid which is used for closing a container (15) having means on the inner side of screwing on to the neck (2) of a container. Internally, the lid has an inner lid (5) which is secured in the lid (1) by at least one securing means. The object of the invention is to provide a lid which is easy to open without using a great force or by using a tool, and which may simultaneously be disposed of without significant environmental impact. This is achieved by a lid (1) whose collar (3) has at least one projection (13) which points radially toward the centre and which extends from the inner side of the collar (3), wherein, during unscrewing of the lid (1), the projection (13) presses the edge of the inner lid (5) at least at one point out of contact with the upper edge of the package neck. This ensures venting of the volume of the container with a relatively weak torque.

Abstract: Closure for containers, comprising a locking ring (1) which in situ surrounds the container along the whole of its outer periphery. At least one area of the container closure comprises means which allow a substantially reversible increase in the circumference of the locking ring. The container closure also comprises at least one lock-release part (2) on the radially external side of the locking ring, and which in at least one end is fastened to or constitutes an integrated part of the locking ring (1), and which under the influence of a force results in an increase in the circumference of the locking ring (1). There is hereby provided a closure system for containers whereby the container can be opened even by very weak hands, and whereby it is subsequently possible to effect a closing of the container so that this is closed tightly. The opening and the closing are effected without the use of tools.