The CIL-438 is a filtered, non-resettable, three-position (OFF-AUTO-MANUAL) switch designed to provide a momentary electrical connection when it is moved to the manual position. It is typically used to control a modified off cycle of a manually operated fire alarm, disability aid, intercom, or control system. When connected to an appropriate system, the switch allows the user to temporarily bypass the normal operating sequence of the system. The CIL-438 is UL listed for use in Class B wiring in fire alarm systems, providing an extra measure of safety, and features C-UL approval for use as a manual station in life safety applications.