The chip is Siemens TC35.

The performance and SMS of the two devices are same as the original device. The technical parameter refers to the manual.

External aluminium casing
RS232 interface

Support dual-frequency EGSM900/GSM1800, data, tone, SMS and fax.
Standby current: 3mA. Support the transmitting speed of three language coding.
Hands free operation. GSM Phase 2/2+ standard.
Sending tone and data
Voltage: 3.3V~5.5V

Dual frequency GSM900MHz and DCS1800MHz(Phase 2+)
Transmitting power: 2W (GSM900MHz Class 4) 1W (DCS1800MHz Class 1)
SIM Card external
Antenna connected via connector

Working temperature: -20C to +55C
Storage temperature: -30C to +85C
Working current: 300mA
Standby current: 3.5mA(Max. 100μA )

Tone decoding standard: Half speed (ETS 06.20), high speed(ETS 06.10), highest speed (ETS06.50/06.60/06.80)

SMS: MT, MO, CB and PDU
Dimension: 54.5 x 36 x 6.7mm
Audio interface: Analog signal(Microphone, earphone and hands free)

Communication interface: RS232 (Two-way transmission for command and data)
Working voltage of SIM card: 3V/1.8V
Phone book stored in SIM Card
Module reset: AT command or power-off reset

Baud rate of serial port transmission: 300bps...115kbps
Auto baud rate: 4.8kbps...115kbps
Improved service and maintenance via RS232 or SIM interface
Real-time clock: Frequency 32.768KHz

Timer: Program via AT command
Accessories: Antenna, serial cable, power supply converter.
The two devices support the sending/receiving message with the speed of 800 per hour.
Support all of the SMS software of our company.

Applications: SMS advertisement, SMS notification, SMS monitor and SMS query etc. Such as vehicle monitoring and dispatch system, mobile data query system, water resources and electric power monitoring, mobile security exchange and information query, mobile data security query(ID and crime file etc), mobile traffic police data query(vehicle and driver file etc), mobile office and management and the other applications.