D+H LT 84 is a manual control device designed for use with D+H smoke vent and ventilation control panels. It allows for manual opening and closing of drive groups, providing convenient control over ventilation and smoke extraction systems. The LT 84 can be mounted in a 55 mm flush socket for dry rooms or as a surface-mounted version for damp areas. Variants with integrated LED display or automatic weather/temperature switch are also available. Please refer to the control panel instructions for detailed wiring diagrams.