Emergency telephone outside the Pillar Tunnel YD-SDN03-L1/SIP

SC Optical Interface/single-mode fiber; 1; rated sound pressure level; 90 dba [40 cm ahead ]2; voice calling frequency band; 300hz-8Khz 3; operating
temperature; -40-70 °C 4; protection registration; IP655; operating voltage; AC-220V-50HZ access mode open 6; Call mode; one-button call hands-free call 7;
fused fiber mode; built-in fused fiber box, can reserve network exchanger installation location 8; broadcast voice band, 100 HZ-16 khz 9; power amplifier
control interface; power amplifier interface two, broadcast audio output two 10; installation; column type, column chassis installation holes can be customized
according to the project site free of charge