The Qolsys QS1134-840 IQ RECESSED-S Door / WIndow Sensor is our most powerful S-line sensor ever. Leveraging the proprietary S-Line Technology, to encrypt signals sent to the panel. The IQ Recessed-S is installed in the core of your door, forever changing the idea of security and smart home applications. Create rules such as “when door opens, turn on the light” or “if door left open, adjust my thermostat to save energy until it is closed again.”  With the longest and most powerful range of our S-Line, you want to make sure the IQ Recessed-S makes it into every door you own.