Feature: 1. Display: With large screen LCD display, know real time information, with timing, billing, and checking functions, suitable for public telephone. 2. Stable Signal: Adopts SIM 300W module with strong signal and good stability, endure clear sound, noise free, and strong signal reception even in remote areas. 3. Fine Workmanship: Designed with received signal strength display, working status display, caller ID function, dual band GSM working mode, and has high sensitivity. 4. Easy to Operate: The operation mode is the same as that of ordinary telephone landlines, and the automatic IP function can be preset through the telephone set. 5. Practical: No need for ground wiring, easy to install, can be connected to all the voice boxes on the market, anti theft alarm host, and ordering software. Specification: Item Type: GSM DialerMaterial: ABS .Working Method: GSM 900MHz 1800MHz dual frequency Peak Power: 0.25W 0.5W Power Consumption: Static ≤ 25 mA, emission ≤ 400 mA Sensitivity: -104 dB Ambient Temperature: 0 °C-+40 °C Operating Humidity: 45 %-90% Atmospheric Pressure: 86-106 Pka Ambient Noise: