UPDATE: So I bought these about a year ago after a highway accident. I would like to report that the product still works great. After opening the camper for our first outing, I had to inflate the tires as usual. The overall pressure in each tire was lower than in previous years, only 15psi instead of 20-25psi. I still recommend this product and it only works with the included controller. Batteries still work and will be replaced if necessary. Happy follower! Bought these for my 30ft street trailer. After the explosion and without knowing it while driving. I figured it would be better to invest in something to keep an eye on the tires. After driving 200 miles I found them to work exactly as advertised. The alarms were loud and annoying when they went off as a test. And in the event of a stuck brake, the temperature readings were helpful. I even liked the solar charging which freed up a USB outlet. The whole installation took about 10 minutes per wheel. It has a support nut and a rubber boot to protect the sensors. Only time will tell if they will last for many years. I plan to change the button cells in the sensors every year. Update: After the trailer has been up for about a month. I placed the receiving unit in sunlight to keep it charged. The tires lost air around 1-2psi, which isn't bad at around 70F. I've done 800 miles and still love keeping track of tire pressure and temp.