Features:
1.GSM: 900/800MHZ
2.Adopts nokia mobile module
3.Compatible to most telephones.
4.Provides reversal polarity sign
5.Have a LCD display call out number,call in number,time,billing metering and etc.
6.Caller id. With DTMF
7.With battery, working time 2 hours, stand by 12hours…Detail
