A slide ring seal, including a slide ring and a counter-ring, the slide ring and the counter-ring sealingly contacting each; other so as to be relatively rotatable at their sealing surfaces and so as to be acted upon by spring tension under axial prestressing. In one embodiment, a highly collimated beam is passed through a holographic diffuser to create a well defined cone angle for the light emanating from each point on the diffuser. The neck exterior surface includes at least one spiral thread portion. The sequences may be performed on a periodic basis as well as in response to inputs corresponding to alarm conditions and transactions conducted at automated banking machines or other devices. A method of operating an electronic banking terminal is also disclosed.