Tire monitor systems - aftermarket.

I'm on year 5 of this one. I have only had to replace the batteries once so far.

Tymate RV Tire Pressure Monitoring System - M12-3 Tire Pressure Monitor System (0-145 PSI) with Solar Charge, 5 Alarm Modes, Auto Sleep Mode, LCD Display, RV TPMS with 4 Sensors, Easy to Install https://www.amazon.com/dp/B07S7CP3PB?tag=fabo03-20