Here are a couple of pictures of what the TPMS looks like. There are 6 individual transmitters that fit on the valve stem. You remove the valve stem cap and screw these on.
And of course, the other picture is the display, showing the current tire pressure. If a tire gets too low or the temp gets to high (all configurable in the system) and alarm goes off and the new info is displayed on the monitor.
Not a bad system for $130.00. Of course, it all depends on how long it lasts and how accurate it remains.