SIM 900A GSM GPRS Module with RS232 Interface and SMA Antenna is built with Dual Band GSM based SIM900A modem from SIMCOM. It works on frequencies 900MHz. SIM900A can search these two bands automatically. The frequency bands can also be set by AT Commands. The baud rate is configurable from 1200-115200 through AT command. SIM900A is an ultra compact and wireless module. The Modem is coming interface, which allows you connect PC as well as microcontroller with RS232 Chip(MAX232). It is suitable for SMS, Voice as well as DATA transfer application in M2M interface. The onboard Regulated Power supply allows you to connect wide range unregulated power supply. Using this modem, you can make audio calls, SMS, Read SMS, attend the incoming calls and ect. through simple AT commands. This is a complete GSM module in a SMT type and made with a very powerful single-chip, allowing you to benefit from small dimensions. SIM 900A GSM Modem with serial and TTL outputs. Features/Specs 1. Option for connecting MIC and SPEAKER directly to GSM MODEM for calls (LINE IN also available) 2. Supports communication through RS232 with DB9 Connector, TTL Pins and I2C Pins 3. CALL, SMS, GPRS facility – MIC input, LINE input and SPEAKER output pins Note: Product Images are shown for illustrative purposes only and may differ from actual product.