Door and window sensors tell your system when an entry point opens. GlassProtect tells it when a window breaks. The sensor mounts on the interior wall near the windows it's protecting — not on the glass itself — and its microphone listens for the specific two-stage sound pattern of glass breaking: first the impact, then the shatter. Both have to register within about 1.5 seconds for the alarm to trigger. That's what separates it from a simple noise detector, and what keeps everyday sounds from causing false alarms. One GlassProtect covers up to 30 feet in a 180° arc, so a single sensor can protect multiple windows in the same room. It runs on a pre-installed battery for up to 7 years and pairs with your Ajax hub the same way every other device does — scan, mount, done. We recommend one per room that has multiple windows and sits on or near the ground floor. One important note: GlassProtect is designed for standard glass. It will not detect glass that has protective film applied to it — if that applies to your windows, reach out and we can help you find the right solution.