Abstract: An adaptor and a closure are formed with precision surfaces as by injection molding so that the closure can be attached to the adaptor without the use of excessive force to create a secondary seal. The adaptor-closure can then be attached to an imprecisely formed threaded container such as an extrusion-blow molded bottle to create a primary seal. The adaptor is permanently retained on the container with securing by thread wedging, cooperating ratchet teeth or the like.

Abstract: A securing mounting arrangement is provided for a blowout magnet (16) and an electromagnetic relay (11) for increasing its capacity for switching larger values of voltage and current than possible without the arc extinction characteristic provided by the blowout magnet. In order to provide an electromagnetic relay suitable for applications subject to extreme vibration and shock, such as is type of automotive applications, the primary component of the mounting arrangement is integrally molded in the base (12) of the housing while the relay itself and the cover (13) of the housing all provide portions of a cavity wherein the magnet is contained.