Choose a window sensor that matches both the wireless frequency and protocol supported by the existing security panel and receiver, with available options using 319.5 MHz, 345 MHz, or 433 MHz systems. Check the panel documentation or receiver specifications before selecting a sensor, because sensors designed for one frequency or protocol may not communicate with another, and some formats exclude encrypted systems.

When mounting wireless window sensors, use a stable surface and align the sensor with its magnet so the contact stays within the specified 0.625-inch gap when the door or window is closed. Confirm that the sensor’s wireless frequency and protocol match the security panel or receiver, and choose a mounting location that supports reliable wireless communication.

A window sensor with an external input is useful when the installation needs one wireless transmitter to monitor a separate wired contact, such as a recessed contact or an access point that cannot accommodate the sensor’s built-in magnet. This configuration can help installers cover specialized window frames, secondary openings, or other hard-to-reach contacts while connecting the sensor to a compatible security panel.

When selecting wireless window sensors, compare the sensor’s wireless protocol and frequency with the compatible alarm panel or receiver, such as 319.5 MHz, 345 MHz, or 433 MHz systems. Also consider surface-mount installation, low-profile design, wireless range, the 0.625-inch magnet gap, battery life of five to eight years, and interchangeable cover options for residential or light commercial applications.