Abstract: The invention permits a cable to be connected to an item with an opening or threaded hub, for example a junction box. The invention can accommodate a wide range of cable sizes and enables an operator to quickly form an effectively water-tight and gas-tight connection with the junction box, thus sealing the junction box from contaminants. The apparatus of the invention has an opening for receiving the cable and a plurality of flexible fingers extending peripherally around the cable. An elastic cover assembly encloses the fingers and comprises an elastic sleeve enclosing a hollow core member. Initially, the sleeve is stretched on the hollow core member, which member is then progressively removed to permit the sleeve to collapse onto the fingers to force the fingers against the cable, enhancing gripping of the cable. A shoulder adjacent the fingers and projections on the fingers enhances grip of the sleeve.