Skylink M-Series Basic Kit 4-Zone Alert Alarm System, Works with up to 16 Wireless, Package Includes Door, Motion Sensor, and Keychain Remote. No Monthly Fees, White Easy installation and do-it-yourself (DIY) no monthly fees Arm & disarm the system with keychain remote of keypad Get alarm (siren) or alert notification (beep) when sensor is activated Add up to 16 wireless accessories/sensors to the main unit Add an optional internet hub (model HU-100) to control your alarm system with your smartphone, anywhere in the World