1Adopting SIM300W module with strong signal and good stability. 2With timing, billing, and checking functions (for public telephones). 3With receiving signal strength display, working status display, caller ID function. 4Fully automatic IP function (it can be preset by phone). 5It can be connected to the market with voice box, burglar alarm host, ordering software.Features: Adopting SIM300W module with strong signal and good stability. No need for investment in ground cable lines, easy to install. Large screen Chinese LCD display. With timing, billing, and checking functions (for public telephones). With receiving signal strength display, working status display, caller ID function. The operation mode is the same as that of ordinary telephone landline. Fully automatic IP function (it can be preset by phone). It can be connected to the market with voice box, burglar alarm host, ordering software. Specification: Condition: 100% Brand New Material: ABS plastics Color: As picture shown Frequency range: dual band: GSM 900MHz/1800MHz GSM 900MHz (transmit 890-915MHz / receive 935-960MHz) / GSM 1800MHz (transmit 1710-17850MHz / receive 1805-1880MHz) quad band: GSM 850/900/1800/1900MHZ Peak power:0.25W/0.5W Power consumption: Static 25 mA, emission 400 mA Sensitivity: -104 dB Internal voltage: DC 5V / 1A Ambient temperature: -10 C ~+40 C Operating humidity: 45 % to 90 % (without condensation) Atmospheric pressure: 86~106 Pka Ambient noise:Antenna overflow: 3.5dB (omnidirectional) AC power supply: 90-240V ac 10%, frequency 47-54Hz DC power supply: 12V Packing size: 21*15.5*7.5cm/8.3*6.1*3.0in Functions: 1. With 300W communication module, the signal is good, the long-term work stability is good, the sound quality is clear, the call is free of noise, the call is not dropped, and the signal is strong even in remote mountainous areas. 2. Many years of experience in the production of wireless access fixed-board products, the quality is guaranteed, the repair rate is not more than 2%. 3. The monthly s are over 10,000 units, and the productivity and similar products are cost-effective. The provinces and cities across the country have competitive advantages. 4. There are large LCD screens in Chinese and English, showing the signal receiving intensity, specific time, call history, talk time, and call charge. 5. With real meter function, alarm billing mode function, with multiple groups of billing functions, can be used as a public phone, completely eliminating the meter and saving costs. 6. Sup