I have the RT 66 Tire Minder. For me it had issues, but now that I have figured these all out it seems to be working perfectly. The Tire Minder has a wireless hub that is mounted somewhere in your RV and is designed to allow the sensors on your tow dinghy to be received and read. Initially my hub, mounted halfway back in my RV near my batteries, was not communicating consistently with the sensors on the dinghy so I would get low signal (LS) alarms. About 2 months ago TireMinder sent me a new hub that is waterproof which I mounted under my coach. I also moved the original hub to my CMax dinghy. Even with this I had LS alarms for the dinghy. To solve this I moved the wireless hub in the dinghy to sit on the driver's seat when I am towing it and now it seems to be working reliably.
On my last RV trip I was going down a very long hill and one of the front tires gave me a high temperature alarm. Even though I had been using my grade brakes these brakes were getting dangerously warm The alarm caused me to pull over and run lots of water over my front wheels until they were at a reasonable temperature.
TireMinder hubs are powered 100% of the time, but the monitor goes to sleep when you are sitting stationary for a long time. Even walking about in the RV is enough to wake up the monitor. This is useful to keep a charge in the monitor for quite a long time.