Onvis Contact Sensor CT3

The Onvis Contact Sensor CT3 is a Thread-enabled door and window sensor with native Apple HomeKit support, eliminating the need for a hub or bridge. This compact sensor detects open/closed status and reports directly to your Apple Home through a Thread border router like HomePod Mini or Apple TV 4K. The Bluetooth Low Energy fallback ensures connectivity even without Thread infrastructure.

The sensor features a slim profile that mounts discreetly on doors, windows, cabinets, and drawers. Battery life extends up to one year from a replaceable CR2032 cell, with low battery notifications through the Home app. The Thread mesh network provides reliable, low-latency communication without WiFi congestion.

HomeKit automation enables triggers based on open/closed events—turn on lights when doors open, receive alerts when windows are left ajar, or arm security when leaving home. The sensor pairs directly through Apple Home without requiring the Onvis app for basic functionality. For HomeKit households seeking Thread-enabled contact sensing without hub complexity, the CT3 provides straightforward, reliable detection.