a resilient plastic screw - type closure , for use with any of a number of standard container top designs , is molded with a plurality of indicating members comprising a detachable lower rim of the closure . as initially molded , the indicating members are outside the principal external contours of the closure , but after installation on the container they are tilted inward until retained by locking means within the principal contours . in this condition they are positioned underneath an annular shoulder formed around the neck of the container . thereafter , the closure cannot be removed , or substantially loosened , without partially or wholly detaching the indicating members from the body of the closure .