Using SIM300W module, strong signal and good stability. 2. It has timing, billing and inquiry functions (public telephone). 3. It has the functions of receiving signal strength display, working status display and caller display. 4 Fully automatic IP function (can be preset by phone). 5. Can be connected to market voice box, anti-theft alarm host and ordering software. Features: Using SIM300W module, strong signal and good stability. No need to invest in ground wires, easy to install. Large screen Chinese LCD display. It has timing, billing and inquiry functions (public telephone). It has the functions of receiving signal strength display, working status display and caller display. The operation method is the same as an ordinary telephone landline. Fully automatic IP function (can be preset by phone). Can be connected to the market for voice boxes, anti-theft alarm hosts, and ordering software. Specifications: Condition: Material: ABS plastic Color: As shown in the picture 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, transmit 400 mA Sensitivity: -104 dB Internal voltage: DC 5V / 1A Ambient temperature: -10℃~+40 C Operating humidity: 45% to 90% (non-condensation) Atmospheric pressure: 86~106 Pka Environmental 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*3.0 inches Functions: 1. Using a 300W communication module, it has good signal, good long-term working stability, clear sound quality, no noise during calls, and no dropped calls. The signal is strong even in remote mountainous areas. 2. With many years of experience in the production of wireless access fixed board products, the quality is guaranteed and the repair rate does not exceed 2%. 3. The monthly output exceeds 10,000 units, and the production capacity is highly cost-effective compared with similar products. All provinces and cities across the country have competitive advantages. 4. Large LCD screen in Chinese and English, showing signal reception strength, specific time, call history, call time, and call cost. 5. It has real meter function, alarm billing mode function, and multiple sets of billing functions. It can be used as a public phone to completely eliminate the electricity meter and save costs. 6． Soup