Constructed with metal cabinet, the speaker is ideal for use in a voice alarm system. Can be surface- or flush- mounted to the wall. Either concealed in-wall wiring or exposed wiring can be used for speaker cable connection. The speaker structure of direct wall-mounting with screws prevents the speaker from falling easily even if an outward force is applied to. The input impedance can be easily changed by changing the tap position of the transformer. The built-in 16 cm double cone speaker unit delivers high quality sound. Two steatite screw terminal blocks (1 cable to 1 connection type) make bridge connection easier.