I bought it off eBay new and it appears to work when you put the batteries in. Unfortunately after trying to pair it with Open Hab its unable to find it. I did a factory reset on the sensor and tried repairing it. The device flashes when you press the pair button 3 times within 1.5 seconds so its definitely working but suspect OpenHab can’t find it or its not supported. I cant see anything in the logs either.