1. Cabinet:aluminum alloy die - casting, high anti-violent, able to glisten, convenient for looking for
2. Door cover:orient automatically and good self - closing, convenient for use.
3. Handset:made of special engineering plastic, high anti-knock resistance. high tensile strength resistance and high anti-violent.
4. All of the components including handset telephone receiver and transmitter, keypad, buzzer, circuit board and cabinet are designed to be multi - layer waterproof and dust - proof which is up to Class III grade. The whole machine is up to national standard GB4208-93 IP 66.
5. Phone is provided with high stability, high anti-jamming capability, and it is up to national standard GB/T 15279-94.

Specification:
1. Applicable for various types of SPC exchange and dispatching exchange system with feeding voltage of 48-60V.
2. Ambient temperature:-30�}~60�} Relative humidity:10%~95%
Atmospheric pressure: 86~106Kpa Circumstance noise:? 60dB(A)
3. Sound level of ringing:?70dB(A).
4. Standard frequency:low frequency group:697. 770. 852. 941Hz,
high frequency group:1209. 1336. 1477Hz, frequency deviation:?��1.5%
If service line is a 3Km signal - level:
Standard frequency:low frequency group:-9dB��3dB, high frequency group:-7dB��3dB, level difference between low and high frequency of compound signal:2��1dB, the total distortion caused by intermodulation of harmonic wave is lower than the basic level by at least 20dB.
5. Call transmission index:(5KM)SLR?12,RLR?-1,STMR?10, output impedance is 600��.
6. Super strong function is available for dialing 12 groups of numbers stored in the memory (maximum length of each number is16 digits)

1. Applicable for various types of SPC exchange and dispatching exchange system with feeding voltage of 48-60V.
2. Ambient temperature:-30�}~60�} Relative humidity:10%~95%
Atmospheric pressure: 86~106Kpa Circumstance noise:? 60dB(A)
3. Sound level of ringing:?70dB(A).
4. Standard frequency:low frequency group:697. 770. 852. 941Hz,
high frequency group:1209. 1336. 1477Hz, frequency deviation:?��1.5%
If service line is a 3Km signal - level:
Standard frequency:low frequency group:-9dB��3dB, high frequency group:-7dB��3dB, level difference between low and high frequency of compound signal:2��1dB, the total distortion caused by intermodulation of harmonic wave is lower than the basic level by at least 20dB.
5. Call transmission index:(5KM)SLR?12,RLR?-1,STMR?10, output impedance is 600��.
6. Super strong function is available for dialing 12 groups of numbers stored in the memory (maximum length of each number is16 digits