The SP20ST indoor Sounder generates 94.4 dB at a distance of 1m and can be programmed to work with a montone or bi-tonal frequency. Suitable for local signalling (not valid for fire alarms). The quality of the ABS plastic box and Mylar cone speaker protection ensures high reliability and durability of the Sounder. The design of the mounting surface facilitates installation in a wide variety of configurations. The SP20ST is an integrated Sounder that connects directly to the bell output of any panel. The colour and texture of the cabinet has been designed to blend with the colours and types of most common wall surfaces.