Beautiful and smart frame .module designed, install and dismantle easily. Resin composed with anti-destroyed capacity, as well as high waterproof , antisepsis and antirust ,too. Four grade volume adjustment from low to high . Emergency calling ,redial, hang up available Store answering numbers apart , one of them available to connect smart or IP platform by users. Technical parameters Environment Operating Temperature -10°C ~ +40 °C Relative humidity 0% ~ 95% Noise ≤ 60dB(A) Atmosphere pressure 86 ~ 106 kPa Electricity Transmission Performance Sending Loudness Rating(SLR):≥ 2dB@0km,≤ 12dB@ 5km Receiving Loudness Rating(RLR):≥ -8dB@0km,≤ -1dB@5km Side-Tone Masking Rating(STMR):≥ 3dB@0km,≥ 10dB@5km Ring Sound on top class:≥70 dB(A) Working frequency 300-3400Hz Dialing types DMFT Frequency parameters 1209Hz 1336Hz 1477Hz 1633Hz 697Hz 1 2 3 A 770 Hz 4 5 6 B 852Hz 7 8 9 C 941 Hz * 0 # D DTMF Transmission Level High Frequency circle :–7 dBm ± 3 dB, Low Frequency circle:–9 dBm ± 3 dB Difference: ≤1.5% for single frequency DC Impedance Off-hook : ≤300Ω On-hook: ≥5MΩ Packed files Payphone size 270mm*190mm*135mm Packing size 290mm*210mm*155mm G.W/N.W 6.5Kg/5.5Kg