I bought it and its a waste of money in my opinion.
1) It does not monitor the actual pressure like the ones in my truck rims.
2) It will only report when the tire goes flat - loses half the pressure.
3) There is no easy way to reset the reporting pressure to something higher; although their web site says it is possible.
4) The transmitter screws onto the rubber valve stem. At highway speed, the heavy transmitter bends the valve stem until the transmitter hits the rim of the wheel. I believe this stress on the stem will actually cause a leaker at the wheel-stem hole.
5) To prevent that, the valve stems need to be replaced with all metal valve stems. (which is a good idea in any case since the rubber ones are only rated to 50PSI). I needed to put 100PSI stems on my wheels when I got the D rated tires mounted.
6) The reciever in the truck ties up a lighter port. With the GPS, Ipad and Phone chargers, all 3 of of mine are used. I added 3 more in the rear of the crewcab for all the electonics we seem to need, but it is a hastle in a truck with only two.
7) When I had my blowout, it was LOUD and even though my caps were back in the box, I had no trouble figuring out it was on my camper.