X-Sense XS01-WX WiFi mini smoke detector with replaceable lithium battery that lasts for 1 year, EN14604 certified. Connects to the X-Sense Home Security app via 2,4GHz WiFi. Receive instant notifications for alarms, malfunctions, and low battery levels, wherever you are. You can also easily test the detector from the app. The connection to the app can be established without a Base Station/Gateway. Please note: the XS01-WX cannot be wirelessly linked to other X-Sense detectors. The XS01-WX therefore remains a stand-alone smoke detector. If your WiFi fails or a malfunction occurs, the smoke detector will still sound the alarm autonomously, but you will not receive any notifications on your app.