I looked at these but did not like the fact that the gauge was in the cig plug which meant it would have been hard to see. (I know you could connect it via a cable to the cig plus.) I ended up getting a 'Safe T Tyre' set up, 8 sensors to fit the car and the caravan. The large gauge sits on the dash and is very easy to see. I know the alarms will activate depending on the settings you have set, but I like to be able to keep a bit of an eye on the temps and pressures. The price was not as cheap as the Ebay one but I have seen the 'Safe T Tyre' in use and spoken to owners and so far I am very impressed with how it is working. I phoned to order it on a Tuesday afternoon and it was in my hands the very next day, in Qld. Kevin