BS-680FC EN 54-24 metal-body Wall Mount speaker Constructed with metal cabinet, the speaker is ideal for use in a Voice Evacuation System. The speaker can be surface- or flush- mounted to the wall. Either concealed in-wall wiring or exposed wiring is possible. The input impedance can be easily changed by changing the tap position of the transformer. A built-in 6-inch (16 cm) double cone speaker unit delivers high quality sound. Two ceramic screw terminal blocks (1 cable to 1 connection type) make bridge connection easier. The BS-680FC is certified with EN 54-24.