... 1. Wireless GSM Digital Mobile Network: GSM900MHz/1800MHz,850/900/1800/1900MHz.2. LCD Display, Large, easy to read, four lines ... Relative Humidity: 10% ~ 95% Environment Noise: ≤60dBAOperating Frequency: GSM 900/1800 MHzTransmit Power: 2W Receiving sensitivity: -104 dBm