GSM (Model: S1804G)
Support GSM 900/1800MHz or 900/1800/1900MHz or 850/1800/1900MHz or 850/900/1800/1900MHz.

CDMA (Model: S1804C)
Support CDMA 450/800/1900MHz single band.

S1804 series
4xFXS which can connect to normal telephone, PBX or connect to FXO VoIP Gateway for call termination.
Support polarity reversal, DTMF, Caller ID.
SMA-KY antenna connector.
Support PC NMS, PC billing, external billing machine.
With Cascade port, which can cascade maximum 4 units uo to 16 lines and managed by one PC.
Support GSM and CDMA mixed in one unit, such as 2 lines GSM and 2 lines CDMA
Diemension: 482mmx263mmx44mm, 19inch.