The cable lead-through has a connector for installation into the opening of an apparatus housing (6), the connector being made of non-conducting material in the form of a retaining block (2). There is a flange (8) for laying over the rim of the opening, a clip (11) for the inside of the rim, a hole (3) for the cable with an associated tension relief device (4). The tension relief device is totally or partly within the length of the block. From the outer end of the cable hole projects a shell-like stabiliser for the cable. This is a separate item made of elastic material joined by a rapid-weld process or a plug fitting to the block.