Payphone with 800, 450 or 1,900MHz CDMA Frequency, Two-way SMS, Voice Mail and Caller ID... Country of Origin:China (mainland)Brand Name ... incoming and outgoing calls Adaptive to wide range of voltage with low power consumption Fast intelligent dialing numbers Sample operation as ... °C Relative humidity: 10 to 90% Payphone with 800, 450 or 1,900MHz CDMA Frequency, Two-way SMS, Voice Mail and Caller ID