Macally SecurityMan Air-Alarm is a state-of-the-art wireless alarm system kit for homes and businesses. It is user-friendly easy to use protecting homes/businesses at a minimum cost of investment. Do-It-Your-Self installation and self-monitoring alarm system without monthly fees is a key benefit for users. The system will alert by phone calls to owner through a series of enlisted phone numbers. The owner can then dial into the host to armed or disarmed using the phone¿s numeric keypad. Air-Alarm system can be upgraded by adding up to 60 wireless sensors, sirens, and up to 8 remote controllers. more info