... data surveying and remote monitoring in shops, villas, financial offices and departments of electricity, petroleum, coal, government, public security and other unattended ... English message;6. The main unit can be used as a telephone;7. Arm, disarm, monitor, and intercom by phone;8 ... ,900/1800/1900 MHz,so it is available all over the world.4.What is the warranty and delivery time? ------ We provide 2 ...