Wireless Solar TPMS for RV, Bus, Caravan, Motorhome, Trailer & Truck - DIY Easy Installation with 8 Cap Sensors (0-188 PSI / 0-13 BAR) | Real-Time Tire Pressure Monitoring for Safer Road Trips & Heavy-Duty Travel

A few things set this TPMS set apart from cheaper alternatives. First, it can monitor up to six tires, making it sufficient for most trailer/pickup truck combos and most RVs (except class A motor homes which it may fall two short of, but a two-axle fifth wheel or two-axle trailer and truck it's perfect for). Second, this set comes with a repeater for long trailers/RVs. Third, there's a solar cell for charging the main unit.The box includes six monitors that screw onto the end of the valve stems in place of the valve caps on the tires you want to monitor. Each monitor is powered by a CR1632 battery. Before the monitors are screwed in place a small nut is threaded deep onto the valve stem. After the monitor is screwed on, the nut is backed up tight against the monitor to hold it in place so that it doesn't rattle off or get stolen easily.The set comes with a repeater for the furthest monitors. Unfortunately, this brings up a strange design decision made by the manufacturer. Though the main LED console unit has a solar panel on its back to power it, there's no such solar panel on the repeater: you must attach the repeater to battery power. You may not need the repeater if your trailer isn't long, but if you do, you need to wire the repeater into power. Wherever you place it, there must be a wired power supply available nearby to service it. I think it would have made more sense to have the repeater solar powered and the main console run solely off USB power via a cabin power supply. The main unit attaches to the rearview mirror and will power its battery by sun, or you can use a power source and USB-C cable to power the main unit if weather is bad and the battery no longer has power.I suspect many users will choose to plug the console into vehicle power rather than rely on the solar cell. This is a small, helpful and accurate TPMS system for bigger vehicles.