I worked fine at first though was a bit fiddly to set up. Once we got it going it was grand until 6 months later when the battery in the outdoor device needed to be replaced. And that was the end of the outdoor data transmission - the outdoor device still works and shows the outside temperature, however, the data is not transmitted to the indoor weather station. I would therefore not buy the device again. Having said that, the weather station still displays the indoor temperature and humidity correctly and reliably 2 years on.