Upon activation, when fitted with the Euro Stopper sounder, wireless & relay cartridge will emit a localised 96 dB alarm (powered by a 3V lithium battery, included). The relay facility will send a triggering signal to an additional panel or beacon and the wireless technology will trigger an STI receiver, providing a visual and audible indication, remotely. The cartridge is also supplied with a service pin. Quantity: 1 NB: STI wireless receiver sold separately.