I have had the TST 507 with flow through sensors since 2015 or '16. I have had one sensor fail and the B&W display has always been hard to read. My only other complaint is you can't (aren't supposed to) run the flow through sensors on rubber valve stems and the fact that the little set screws are a PITA. I had metal stems put on my 29rs but my other trailers are still rubber as I move the sensors from RV to gooseneck to flat bed depending upon what I am towing.

On our last trip to CO last month my display fell from the windshield, bounced off the dash then the console then hit the floor. Case got busted and display doesn't come on.

I bought the new TST 507 with the color display and the cap style sensors. So far I am very happy with this. For one the display is easy to read (BTW this time I mounted the display directly below my rear view mirror and made a tether out of a mini bungee cord so if it comes loose it won't fall.
Second the caps are easy to remove. I didn't use the locking nuts so I can easily remove them to store them in the truck (to save the battery) or to move from trailer to trailer.
Several of my trailers have the same tire pressure so for those I don't have to change any settings. The cargo trailer has lower ratings and the gooseneck has higher but once you learn to change the settings it doesn't take long.


When I was taking the batteries out of the old flow through sensors I noticed one had some water get in but was still working. I would be interested in selling the old ones if anyone is interested send me a pm- they will work with the new system btw as does my old repeater