SK-200 SkylinkNet Connected Wireless Alarm System, Security & Home Automation System, iOS iPhone Android Smartphone Compatible with No Monthly Fees. Arm & disarm the system and see the sensor status with the Skylink Smartphone App. Receive push notifications anytime a new activity takes place No Monthly Fees or Contract.If motion is detected, a red led light inside the sensor will flash.Sensor will not be triggered by new motion unless no motion has been detached for 15 second Easy installation and do-it-yourself (DIY) Add up to 100 sensors and controllers for additional control