An opening device of plastics material, which is suitable for closing and re-closing of a metal can end, for example. The opening device has two distinct parts: a base plate and a tab, which are joined together by an integral rivet. The opening device is used to close an aperture in the metal panel of a can end by fitting the base plate to the underside of the panel and connecting this to the tab on the top of the panel. A sliding action by pulling or retaining the tab actuates movement of the base plate for opening and reclosing of the closure panel.