The Simplex 4905-9946 is a surface-mount adapter skirt designed for use with compatible Simplex wall-mount notification appliances. The skirt provides a finished mounting solution when devices are installed on surface boxes or when additional depth is required for wiring.

The adapter surrounds the base of the signaling appliance to conceal wiring and mounting hardware while maintaining proper device alignment with the wall surface. The component is finished in red to match standard fire alarm notification appliance housings.

This accessory is intended for use in installations where wall-mounted appliances require surface mounting rather than flush electrical box mounting. It is commonly used with compatible Simplex horn, strobe, and horn-strobe appliances.