The Ring Alarm System Door Sensor is a white wireless device that operates on both battery and wall plug-in power sources. It features a 8-inch LED LCD screen with a 16:9 aspect ratio and a contrast ratio of 50:1. The door sensor is compatible with Amazon Alexa for smart home integration and offers a quick response time of 1ms. With a sleek design and easy authentication via password, this Ring device ensures home surveillance and security with its IP/Network surveillance technology. Additionally, it comes with a 1-year manufacturer warranty for added peace of mind. worked when it was used no refunds no returns
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