... MTK3329 chipset, module from Holux or Royaltek, L1, C/A code,1575.42MHZI/OInputsEmergency Button, 2xLow Level Voltage, ... internal, 12v, 500mAhBackup Time40minutes~90minutesSerial PortRS232Two ports, external intelligent devices such as cameras, PDA and other terminalsBaud Rate51200bps ... temperature sensor, fix bar, and RS232 connected device Intelligent GPS car alarm system/gps tracking device/ car gps ...