Abstract: An apparatus for identifying the contents of a cylindrical container. The apparatus comprises a semicircular member mounted on the peripheral surface of the container for relative rotation with respect to the container. The semi-circular member has its ends detachably connected with identification members carrying thereon an information on the contents of the container and provided with a weight mounted on the semi-circular member at the central point thereof whereby the semi-circular member is automatically caused by the weight to move to a position in which the identification members are disposed at positions ready for identification by a person when the container is placed with its end faces disposed in substantially vertical planes.